Ingredients for the Chocolate Cake Batter
- 3 large eggs
- 1 cup granulated sugar
- 1 cup milk
- 1/2 cup vegetable oil
- 2 cups all-purpose flour
- 1/2 cup cocoa powder
- 2 teaspoons baking powder
- 1 teaspoon vanilla extract
- A pinch of salt
- Almond flakes for topping
- Powdered sugar for dusting
This batter creates a soft and fluffy chocolate cake that can perfectly hold the creamy custard layer without losing its structure.
Ingredients for the Vanilla Custard Filling
- 2 cups milk
- 1/2 cup sugar
- 3 tablespoons cornstarch
- 1 egg yolk
- 1 teaspoon vanilla extract
- 1 tablespoon butter
This custard is velvety, smooth, and stable enough to bake inside the cake while remaining soft and creamy.
Preparing the Vanilla Custard Layer
Begin with the custard so it has time to cool before layering it into the cake. In a saucepan, whisk together the sugar and cornstarch. Add the milk gradually while whisking to avoid lumps. Place the saucepan over medium heat and cook until the mixture begins to thicken.
Once the custard starts to bubble, add the egg yolk and whisk continuously. Continue cooking until the custard becomes thick and silky. Remove the saucepan from the heat and stir in the butter and vanilla extract. The butter gives richness and a glossy finish.
Transfer the custard to a bowl, cover the surface with plastic wrap to prevent a skin from forming, and let it cool completely.
Preparing the Chocolate Cake Batter
Preheat your oven to 170°C (340°F). Grease and line a rectangular or square baking pan.
In a large mixing bowl, beat the eggs and sugar until pale, thick, and fluffy. This step helps create a light and airy cake. Add the milk, oil, and vanilla extract, and whisk again until smooth.
In a separate bowl, sift together the flour, cocoa powder, baking powder, and salt. Add the dry ingredients to the wet mixture gradually, folding gently until everything is incorporated. The batter should be smooth and lump-free, with a rich chocolate color.
Assembling the Cake
Pour half of the chocolate batter into the baking pan and spread it evenly. Take the cooled custard and gently spoon it over the batter in a long strip or spread it in a central layer depending on the design you want. The cake in the image has beautiful long ridges formed by piping the top chocolate layer in rows, so if you want that effect, transfer the remaining chocolate batter into a piping bag.
Pipe or spread the remaining batter over the custard, creating parallel ridges for decoration. Sprinkle almond flakes on top—they will toast beautifully in the oven and add light crunch.
Baking the Cake
Place the pan in the preheated oven and bake for 30 to 40 minutes, depending on your oven and pan size. The cake should rise evenly, and the top ridges will become lightly crisp and golden. Insert a toothpick into the chocolate part (not the custard) to check for doneness; it should come out clean.
Allow the cake to cool slightly before removing it from the pan. Once it cools further, dust the top generously with powdered sugar. The ridges will catch the sugar beautifully, giving the cake an elegant appearance that resembles a bakery-style dessert.
Serving the Cake
Slice the cake into squares or thick slices, revealing the creamy custard hidden between the chocolate layers. The contrast in texture makes each bite delightful. You can serve it warm, letting the custard stay soft, or chilled, which gives the filling a firmer and smoother texture.
Pair it with tea, coffee, hot chocolate, or even a scoop of vanilla ice cream. Its balanced sweetness and bakery-like finish make it suitable for birthdays, gatherings, morning breakfasts, and afternoon treats.
Tips and Variations
To make the cake richer, replace half the milk in the batter with warm coffee—it deepens the chocolate flavor. If you prefer a flavored custard, add lemon zest, orange zest, or even a spoon of cocoa to create a dual-chocolate version. Almonds can be replaced with hazelnuts or left out entirely if you want a smoother finish.
You can also transform this recipe into a marble cake by swirling the custard lightly into the batter instead of layering it. For an extra moist cake, brush the sponge with warm milk or simple syrup right after baking.
Final Thoughts
This chocolate custard-filled cake is a gorgeous, comforting dessert that brings together smooth creaminess and rich chocolate flavor. Its striking appearance and tender texture make it a showstopper on any table. Whether you bake it for guests or simply to enjoy a cozy moment at home, this cake promises a delicious experience with every slice.