Italian Soft Plum Cake | Torta Soffice alle Prugne
Updated: 6 days ago
Torta Soffice alle Prugne is the plainest kind of Italian cake and one of the hardest to get right. A soft buttery batter scented with lemon and vanilla, covered so densely with plums that the surface almost disappears under them, baked until the fruit collapses into something close to jam and bleeds a purple halo into the crumb. There is no pastry anywhere: this is not a crostata, not a tart, and no pasta frolla is involved.
The whole problem of the recipe is weight and water. A pound and a half of ripe fruit sitting on a soft batter will sink it and soak it unless three things are done: the plums are macerated and drained, they go on cut side up so the skins face down, and the cake bakes low in the oven so the base sets before the fruit can press into it. Get those right and the crumb stays tender under a caramelised fruit surface.
Yield: 8 to 10 slices, one 9 inch (23 cm) cake. Prep: 25 minutes. Bake: 50 to 60 minutes. Cooling: 45 minutes. Total: about 2 hours. Difficulty: easy to intermediate. Course: dessert, breakfast or merenda. Region: northern Italy, Trentino and the Veneto.
The Story
This is a torta da credenza, a cupboard cake in the Italian phrase, and the name describes how it lives. It sits under a glass dome on the sideboard and gets cut into at whatever hour somebody wants a slice: with coffee at seven, with milk at four, at the end of dinner if nothing else has been made. The category has no real equivalent in French pastry, which builds cakes for occasions rather than for the sideboard.
Plums take the late summer and early autumn slot in that rotation, between the cherry cakes of June and the apple cakes of November. The version with halved fruit pressed cut side up across the whole surface belongs above all to the north, to Trentino and the old Habsburg border country, where the Central European Zwetschgenkuchen has long been part of the repertoire. The Italian treatment is lighter: a well leavened butter batter perfumed with lemon rather than cinnamon, and no streusel.
The fruit has a name in Italy that the English word blurs. Susine are the round juicy plums eaten out of hand, while prugne proper are the small oval purple ones sold in the United States as Italian prune plums: dense flesh, a stone that comes away clean, and enough acidity to stand up to butter and sugar. Those are the baking plums, grown across Emilia, the Veneto and Trentino, and the ones this cake was built around.
Ingredients
For the batter
All purpose flour, 2 cups (250 g)
Baking powder, 2 tsp (8 g)
Fine sea salt, 1/4 tsp (1.5 g)
Unsalted butter, softened to about 65°F (18°C), 1/2 cup (115 g)
Granulated sugar, 3/4 cup (150 g)
Eggs, large, at room temperature, 3
Whole milk, at room temperature, 1/2 cup (120 ml)
Pure vanilla extract, 1 tsp (5 ml)
Finely grated lemon zest, from 1 lemon
Fresh lemon juice, 2 tbsp (30 ml)
For the plums
Ripe but firm plums, weighed after stoning, 1 1/2 lb (680 g)
Granulated sugar, 2 tbsp (25 g)
Fresh lemon juice, 1 tbsp (15 ml)
Pure vanilla extract, 1/2 tsp (2.5 ml)
For finishing
Unsalted butter, melted, 1 tbsp (15 g)
Granulated sugar, for the surface, 2 tbsp (25 g)
Sliced almonds, optional, 2 tbsp (15 g)
Powdered sugar, for dusting, optional and used very lightly
Oven: 350°F (175°C), rack in the lower third. Pan: 9 inch (23 cm) springform, buttered, base lined with parchment, then floured.
Preparation
Choose and taste the plums
Buy fruit that is ripe but still firm. Very hard plums have no flavour to give up, while overripe ones release so much liquid they leave a sodden band inside the cake. Italian prune plums are best when the season offers them, combining concentrated flavour, dry flesh and acidity, but any good red or purple plum works. Taste one raw: if it has no character, baking will not create any.
Prepare the pan and heat the oven
Heat the oven to 350°F (175°C) with a rack in the lower third, where the base heat sets the bottom before the fruit can press into it. Butter a 9 inch (23 cm) springform generously, line the base with parchment, butter that too, then flour the interior and tap out the excess. A cake carrying this much juicy fruit is too fragile to invert out of a solid pan.
Macerate and drain the plums
Halve the plums, lift out the stones and quarter any large ones so no piece is much more than 1 inch (2.5 cm) across. Toss them with the 2 tbsp (25 g) of sugar, the 1 tbsp (15 ml) of lemon juice and the vanilla, and leave 15 to 20 minutes while you make the batter. The sugar draws surface juice out by osmosis, so it concentrates into a glaze instead of flooding the crumb. Drain it off before the fruit goes on and keep it for the finish.
Cream the butter, sugar and zest
Whisk the flour, baking powder and salt together and set the bowl aside. Beat the softened butter with the 3/4 cup (150 g) of sugar for a full 4 to 5 minutes on medium, until it is genuinely pale, light and visibly increased in volume. Creaming is where the sharp edges of the sugar crystals cut air pockets into the fat, and those pockets are what the baking powder later expands. Cold butter will not aerate at all; glossy greasy butter has already broken. Beat the lemon zest in now.
Add the eggs one at a time
Add the eggs one by one, beating a good 30 seconds after each and scraping the bowl down before the next. Room temperature matters more here than anywhere else: a cold egg chills the fat below the point where it can hold an emulsion, and the batter curdles into a grainy mass that bakes dense. If it splits, add a tablespoon of the measured flour and beat ten seconds. Add the vanilla with the last egg. The mixture should look like a thick glossy mayonnaise.
Alternate the flour and the milk
Add the dry ingredients in three additions alternating with the milk in two, beginning and ending with flour, on the lowest speed and only until each addition disappears. Fold the 2 tbsp (30 ml) of lemon juice through by hand at the end. Pouring all the liquid in at once floods the flour and forces you to beat hard, which is exactly what you are avoiding. Stop while faint streaks are still visible and finish with a spatula.
Judge the batter and fill the pan
The batter should be thick enough to hold a soft peak and drop reluctantly from the spatula. If it ribbons off freely it has been overworked and will bake tough. A properly mixed batter looks slightly rough and matt; an overmixed one is smooth, shiny and pulls back as you scrape it. Scrape it into the pan and level it.
Arrange the plums cut side up
Lay the drained plums over the batter cut side up, packed close enough that they touch and overlap around the rim. The instinct is always to use less fruit than the cake wants, and it is always wrong: the plums shrink by roughly a third and sink partway into the rising batter, so a surface that looks crowded raw comes out generously rather than excessively fruited. Cut side up is deliberate, since the exposed flesh caramelises under the sugar while the skin holds each piece together.
Butter, sugar and bake
Brush the melted butter over the exposed fruit and the visible batter, scatter the almonds if you are using them, and sprinkle the 2 tbsp (25 g) of granulated sugar evenly across the plums. Bake at 350°F (175°C) for 50 to 60 minutes, and do not open the door for the first 30 while the crumb sets around the fruit. If the rim or the almonds colour too fast after about 40 minutes, lay foil loosely over the top and carry on: this is a heavy wet cake and it needs the full time.
Test between the fruit, then glaze and cool
The cake is ready when the surface is deep golden, the plums have collapsed and darkened at the edges, the sides have begun to shrink from the pan, and a skewer pushed into the batter between two pieces of fruit comes out with moist crumbs but no wet batter. Testing through a plum reads wet and tells you nothing. Brush the reserved macerating liquid over the surface the moment it leaves the oven, rest it in the pan on a rack 20 minutes before releasing the ring, then cool another 25.
Plating
Cut with a long thin serrated knife using a sawing motion rather than pressing straight down, and wipe the blade between slices so the fruit does not drag purple across the crumb. Serve generous wedges on plain plates, because the cake is already busy and a patterned plate fights the fruit. Dust with powdered sugar at the last moment or not at all, never before the cake is completely cool.
Serve it just below room temperature, around 68°F (20°C), where the butter in the crumb is soft and the fruit still tastes of fruit. Never straight from the oven, and never fridge cold, which mutes everything. A spoonful of lightly whipped unsweetened cream, or mascarpone loosened with a little milk, is the traditional accompaniment and the right one, because the acidity of the plums calls for fat beside it rather than more sugar. For breakfast or merenda it needs nothing beyond coffee.
Professional Technique
The technique that decides this cake is creaming. Beating solid butter with granulated sugar is a mechanical process, not a chemical one: the crystal edges of the sugar tear microscopic pockets into the fat, and those pockets are the only air the cake starts with. Baking powder does not create bubbles, it inflates the ones already there. That is why four to five minutes of creaming at about 65°F (18°C) gives a visibly taller crumb than two minutes does, and why butter melted in a microwave can never be rescued: the fat has lost the plastic structure it needs to hold pockets open.
The second technique is emulsion management when the eggs go in. Creamed butter and sugar is a fat continuous system, and each egg adds a large volume of water that must be dispersed into that fat. Added slowly at room temperature, the lecithin in the yolks stabilises the mixture; added cold, the fat firms, the water separates and the batter curdles, and a tablespoon of the measured flour rescues it by giving the free water something to bind to. The third principle is restraint once the flour is wet, since gluten forms instantly and overmixing bakes as a domed cracked top over a chewy crumb.
Texture and Moisture Control
The entire difficulty of this cake is 1 1/2 lb (680 g) of wet fruit sitting on a soft batter, and three measures keep the crumb from going sodden. Macerating and draining removes the loose surface water before it can reach the flour. Arranging the halves cut side up puts the skins face down, so each piece has a barrier between its juice and the crumb. Baking low in the oven sets the base early, before the weight can press through.
The batter is deliberately stiff for the same reason, since a slack one cannot support the fruit and lets it sink into a wet band at the bottom. If the cake emerges with a damp layer along the base, the culprit is almost always overripe plums, undrained macerating liquid, a batter thinned by overmixing, or underbaking. The last is the easiest to correct and the one people reach for least, because the surface looks done long before the middle is.
On the surface the aim is the opposite: as little moisture as possible. The granulated sugar scattered over the fruit pulls the last of the surface water out of the cut flesh and caramelises into a thin crackly faintly bitter glaze, arguably the best part of the cake. Powdered sugar cannot do this, since it dissolves into the fruit and turns to damp grey patches on a warm surface.
Professional Mise en Place
A creamed batter carrying baking powder starts working the moment it is mixed and must not stand on the bench, so the oven and pan are ready before any beating starts.
Equipment and tools
Springform pan, 9 inch (23 cm), with parchment cut for the base
Stand mixer or hand beaters, plus a large flexible spatula
Offset spatula for levelling the batter
Long thin serrated knife for slicing the finished cake
Skewer for testing, and a sheet of foil cut to size for the top
Pastry brush for the melted butter and the glaze
Prepared ahead
Butter, eggs and milk out of the refrigerator a full hour before mixing
Pan buttered, lined and floured, oven up to 350°F (175°C)
Flour, baking powder and salt whisked together in one bowl
Lemon zested and juiced, both quantities kept separate
Plums halved, stoned and macerating in their sugar and lemon
Service setup
Wire rack cleared for the 45 minutes of cooling
Reserved macerating liquid beside the oven for the hot glaze
Cream or mascarpone whipped shortly before serving
Powdered sugar in a fine sieve, used at the table
Chef Tips
Weigh the plums after stoning, not before. Stones account for close to a tenth of the weight, and on 1 1/2 lb (680 g) that difference changes how the cake bakes and how much juice it must absorb.
Rub the lemon zest into the sugar with your fingertips before creaming if you want the citrus to carry further. The abrasion releases the oils straight into the crystals, and the difference is surprisingly large.
Whisk a tablespoon of ground almonds into the flour. It absorbs a little fruit juice as the cake bakes, adds a note that sits naturally beside plums, and is the simplest insurance against a damp base.
If the plums turn out flat, a pinch of ground cinnamon or two drops of almond extract in the macerating bowl will lift them, though good fruit needs neither. Bake the cake the day before you mean to serve it whenever you can.
Common Mistakes
Using too little fruit. The commonest error, and it reduces the cake to an ordinary sponge with a few purple dots on top. The plums shrink by about a third and sink partway in, so pack them until they touch and overlap at the rim. A surface that looks crowded raw is correct.
Skipping the maceration and the draining. Without it the plums loose water goes straight into the crumb and leaves a wet band along the base. Twenty minutes with sugar and lemon pulls that liquid out, and the drained syrup becomes the glaze instead of a problem.
Adding cold eggs to creamed butter. The fat chills, the emulsion breaks and the batter curdles into a grainy mass that bakes dense. Take the eggs out an hour ahead, add them one at a time, and rescue a split batter with a tablespoon of the measured flour.
Testing for doneness through a plum. The skewer comes out coated in fruit juice, which reads as raw batter, and the cake goes back in until it dries out. Push it into the batter between two pieces of fruit instead, where a few moist crumbs mean it is ready.
Dusting with powdered sugar too early. On a warm fruit surface it dissolves into damp grey patches within minutes. Wait until the cake is completely cool, use a fine sieve, and apply it at the table rather than in the kitchen.
Wine Pairing
This is a lightly sweet cake with real fruit acidity, a buttery crumb and a caramelised sugar surface. It does not need a heavy dessert wine and is easily flattened by one. Aromatics, moderate sweetness and lively acidity are what work here.
Moscato d'Asti DOCG: The everyday match and the one most Italian households would actually open. Low in alcohol, gently frizzante and full of peach, orange blossom and sage, it has just enough sweetness to meet the sugar crust without overwhelming the fruit, and the soft bubble lifts the butter in the crumb. Serve at 43°F to 46°F (6°C to 8°C).
Brachetto d'Acqui DOCG: A sweet aromatic red with strawberry, rose and a light sparkle, one of the few reds that works beside a fruit cake without clashing. Its berry perfume runs directly alongside the plum, and the modest tannin and low alcohol keep it from bullying a delicate crumb. Serve cool, at 50°F to 54°F (10°C to 12°C).
Recioto di Soave DOCG: The step up in concentration when the cake closes a proper dinner. Dried Garganega gives honey, apricot and candied citrus, with acidity high enough to cut the butter and a faintly almond finish that suits the sliced almonds on top. Sweeter than the cake, as a dessert wine should be. Serve at 50°F to 54°F (10°C to 12°C).
Ramandolo DOCG: A Friulian white from late harvested Verduzzo, with dried apricot, honey and a tannic grip unusual in a sweet wine. That grip stands up to the caramelised sugar surface and stops the pairing turning syrupy, while its bitter almond finish echoes the plum skins. Serve at 50°F (10°C).
Colli Orientali del Friuli Picolit DOCG: The elegant choice if the cake is the centre of the occasion. Picolit is delicate rather than powerful, with acacia honey, candied peel and a fine thread of acidity, and it flatters a simple butter crumb instead of drowning it. Pour small measures and serve at 50°F to 54°F (10°C to 12°C).
Storage & Reheating
Keep the cake under a dome or loosely covered with foil at cool room temperature, where it holds for 3 days and is arguably at its best on the second, once the plum juices have settled into the crumb. Do not cover it tightly with film while any warmth remains, because trapped steam softens the sugar crust within an hour. Do not refrigerate unless the kitchen is very warm: the cold firms the butter, dries the crumb and dulls the fruit, and a chilled slice needs 30 minutes back at room temperature before it tastes of anything.
It freezes well. Wrap individual slices tightly in film and then foil for up to 2 months, and thaw at room temperature rather than in a microwave, which steams the fruit and turns the glaze sticky. Five minutes in a 300°F (150°C) oven brings a thawed slice back very close to fresh, and revives a slice from a three day old cake.
Nutrition
Per slice, based on 10 slices from one 9 inch (23 cm) cake:
Calories: 300 kcal
Total Fat: 12 g
Saturated Fat: 7 g
Trans Fat: 0 g
Unsaturated Fat: 4 g
Cholesterol: 80 mg
Sodium: 180 mg
Total Carbohydrates: 44 g
Fiber: 2 g
Total Sugars: 24 g
Added Sugars: 15 g
Protein: 5 g
Lactose: 0.8 g
Principal micronutrients: vitamin C, vitamin K, vitamin A, potassium, anthocyanins from the plum skins
These figures are estimates. Nearly half the sugar comes from the plums rather than the sugar bowl, which is why the batter needs only 3/4 cup (150 g) for eight to ten servings. The cake contains wheat, eggs and dairy, and tree nuts if you use the almonds.
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