Plump late-summer plums, creamy vanilla custard, and a tender oil-based sponge come together beneath a buttery crumble crust in this Rustic Plum Custard Streusel Cake. Baked in a 26-centimeter pan and finished with a snowfall of powdered sugar, it tastes like the love-child of a German Zwetschgenkuchen and a French clafoutis, yet it is assembled with pantry staples and absolutely no rolling pins or pastry fuss. Perfect for Sunday coffee, harvest celebrations, or an easy make-ahead dessert, this cake transforms humble fruit into a show-stopping centerpiece—juicy, sweet-tart, and fragrant with vanilla. One bite evokes orchard vines, warm kitchens, and the simple magic of seasonal baking.
Cooking Time
Active preparation: 25 minutes
Baking: 35 – 40 minutes
Cooling & dusting: 20 minutes
Total: about 1 hour 15 minutes
Yield: 10 – 12 generous wedges
Ingredients
Sponge Base
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1 large egg (room temperature)
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4 Tbsp (80 g) granulated sugar
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8 g vanilla sugar (or 1 tsp pure vanilla extract)
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10 Tbsp (100 ml) neutral oil (sunflower or canola)
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8 g (2 tsp) baking powder
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240 g (2 cups) all-purpose flour
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Pinch fine sea salt (optional)
Fruit Layer
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8 ripe plums (about 415 g), halved, pitted, and quartered
Custard Filling
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1 large egg
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3 Tbsp (60 g) granulated sugar
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8 g vanilla sugar
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4 Tbsp (60 g) cornstarch
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500 ml (2 cups) whole milk
Streusel Crumble
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4 Tbsp (60 g) all-purpose flour
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3 Tbsp (60 g) granulated sugar
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1 Tbsp (20 g) cold unsalted butter, diced
Finishing
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Powdered sugar for dusting
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Butter for greasing the pan
Step-by-Step Cooking Directions
1 Prepare the pan
Grease a 26 cm (10-inch) springform or tart pan liberally with butter. Line the base with parchment if desired for easy unmolding. Pre-heat the oven to 180 °C / 350 °F with a rack in the lower-middle position.
2 Mix the sponge batter
In a medium bowl whisk 1 egg with 80 g sugar and 8 g vanilla sugar until pale and slightly thick—about 2 minutes by hand. Stream in the oil, beating until glossy. Sift flour, baking powder, and salt over the bowl; fold gently with a spatula until no dry pockets remain. The batter will be thick like soft cookie dough.
3 Spread the base
Scrape the batter into the prepared pan. With lightly oiled fingertips or the back of a spoon, press it evenly across the bottom and 1 cm up the sides to create a shallow rim.
4 Arrange the plums
Fan the plum quarters over the batter in concentric circles, cut side up, crowding them slightly; they will shrink as they bake.
5 Cook the custard
In a saucepan whisk together the second egg, 60 g sugar, vanilla sugar, and cornstarch until smooth. Gradually whisk in milk to avoid lumps. Place over medium heat, whisking constantly, until the mixture thickens to a pudding—about 4 minutes after it begins to steam. Remove from heat; pour the hot custard evenly over the plums. Tap the pan once to level.
6 Make streusel
Combine 60 g flour and 60 g sugar in a small bowl. Rub in cold butter with fingertips until sandy crumbs form. Sprinkle across the custard surface.
7 Bake
Slide the pan onto a baking sheet to catch drips. Bake 35 – 40 minutes, until the streusel is golden and the custard puffs around the plum edges. A tester in the cake portion should come out clean.
8 Cool & finish
Cool 15 minutes in the pan, then run a thin knife around the rim and release the springform. When lukewarm, dust generously with powdered sugar. Serve slightly warm or chilled, slicing with a hot, dry knife for neat wedges.
Nutritional Information (per slice, 1 of 12)
Calories : 246 Protein : 4 g Fat : 11 g Carbohydrates : 34 g Fiber : 1 g Sugars : 18 g Sodium : 95 mg
Origins and Popularity of the Recipe
Central Europe—particularly Germany, Austria, and Hungary—has a long tradition of fruit-topped yeast or sponge cakes called Obstboden or Blechkuchen. Seasonal plums star in late August–September, often paired with custard or streusel. This recipe modernizes the classic by using an easy oil sponge (no creaming butter) and cornstarch custard for speed, making it popular on contemporary baking channels for its low-fuss elegance and reliable results.
Reasons Why You’ll Love the Recipe
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One-bowl sponge—no stand mixer required.
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Three textures—soft cake, velvety custard, crunchy streusel.
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Showy but simple—arranged fruit creates bakery looks with minimal skill.
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Make-ahead—flavor improves after chilling; ideal for next-day entertaining.
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Versatile—swap fruit, add spices, or convert to muffins.
Health Benefits
Plums supply vitamin C, vitamin K, and antioxidants like anthocyanins linked to anti-inflammatory effects. Using oil instead of butter in the sponge reduces saturated fat, and milk custard offers calcium and protein. Moderation is key, but compared with frosted layer cakes this dessert is lighter and fruit-forward.
Serving Suggestions
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Accompany with lightly whipped cream or vanilla ice cream.
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Add a spoon of crème fraîche for tang.
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Brew a pot of Darjeeling tea or serve with a medium-body Riesling to echo the tart fruit.
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For brunch, pair slices with salty bacon or aged cheese to balance sweetness.
Common Mistakes to Avoid
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Wet sponge middle—spread batter evenly and keep fruit in a single layer.
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Custard lumps—whisk cornstarch thoroughly into cold milk before heating.
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Soggy crust—bake on lower rack so heat sets the base.
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Underripe plums—choose ripe but firm fruit for best sweetness.
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Over-baking—custard should jiggle slightly; carryover heat will set it.
Pairing Recommendations
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Wine : off-dry Gewürztraminer, chilled Lambrusco.
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Coffee : nutty medium-roast such as Costa Rican.
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Tea : fruity oolong or hibiscus iced tea.
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Cheese : mild goat cheese or aged Gouda on the side for a dessert platter.
Cooking Tips
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Substitute 30 g flour with ground almonds for a nutty base.
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Dust plums with 1 tsp flour if very juicy to minimize bleed.
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Add ½ tsp cinnamon to streusel for autumn warmth.
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For smaller ovens, split batter into two 20 cm pans—reduce bake time to 25 minutes.
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Leftovers freeze well: wrap slices, freeze solid, reheat in a 160 °C oven 10 minutes.
Similar Recipes to Try
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Peach Custard Sheet Cake
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Classic Zwetschgendatschi (yeasted plum slab)
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Raspberry Ricotta Coffee Cake
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Apple Streusel Tray Bake
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Cherry Clafoutis Tart
Variations to Try
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Stone-fruit medley : mix plums, apricots, and cherries.
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Chocolate twist : swap 2 Tbsp flour for cocoa in the sponge.
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Gluten-free : use a 1:1 gluten-free flour blend and add ¼ tsp xanthan gum.
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Lemon vanilla : zest one lemon into the batter and custard.
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Nut crumble : replace half the streusel flour with chopped hazelnuts.
Ingredient Spotlight
Plums—Late-season European plums (Italian prune, Damson) excel in baking thanks to high pectin and balanced sweet-tart flavor. They hold shape, bleed minimal liquid, and caramelize beautifully. Rich in polyphenols, they add not just flavor and color but antioxidant benefits.
Conclusion
The Rustic Plum Custard Streusel Cake proves that sophisticated results don’t require complex technique—just good fruit, a dependable batter, and the patience to let your oven work its alchemy. With its trio of textures and harmonious sweet-tart balance, it’s bound to join your regular baking rotation, ready to delight guests and satisfy spontaneous cravings alike.
Frequently Asked Questions
1 Can I use canned plums or peaches?
Yes, drain well and pat dry; reduce sugar in custard by 1 Tbsp if fruit is syrup-packed.
2 Will frozen plums work?
Absolutely—thaw, drain, and blot dry; add 5 minutes to bake time because fruit is colder.
3 Can I swap vegetable oil for melted butter in the sponge?
Yes; use equal volume melted, cooled butter for richer flavor and slightly denser crumb.
4 How far in advance can I bake this?
Up to 24 hours; chill covered. Dust with fresh powdered sugar before serving.
5 My custard seeped into the cake—is that bad?
Not at all; it forms a marbled cream layer. If you prefer distinct layers, let custard cool 5 minutes before pouring.
6 Can I halve the recipe?
Yes—use an 18 cm pan and bake 25 minutes.
7 What if I don’t have vanilla sugar?
Replace with 1 tsp vanilla extract added with the oil.
8 Is the streusel necessary?
The cake works without it but loses crunchy contrast. Consider sliced almonds as a light alternative.
9 How do I know when it’s done?
Edges darken, streusel browns, and a skewer in the cake (not custard) exits clean. Custard will still wobble.
10 Can I make it dairy-free?
Use plant milk (soy or almond) in custard and coconut oil in streusel; texture remains pleasing though flavor changes subtly.