This is the birthday cake I made for my oldest daughter this year and it hit the spot right away. It is a single-layer, Polish style chocolate sponge cake, made with special dark cocoa powder, baked in a 8-inch spring form. In the recipe below I include options for 3 different cake sizes, for bigger, single-layer variations or elaborate tiered birthday cakes. It is best to prepare the sponge cake ahead of time (1 day before), since it needs to cool down completely (best, if overnight) before you remove it from the baking mold. Once baked and frosted, the cake can be refrigerated overnight, but it tastes best when it’s at room temperature, which is about what it will be once the candles are blown out and the slices put on plates.
As for the frosting, I used an American style chocolate buttercream frosting. It’s perfect for decorating layer and birthday cakes, piping on cupcakes, spreading on brownies and other baked goods. Of course, you can use a store-bought frosting instead, but nothing beats a homemade chocolate buttercream frosting. Only a few simple ingredients: butter, milk, vanilla, sugar, dark cocoa and a pinch of salt to balance out sweetness and round up the flavor. It takes literally 5 minutes to make it and even more importantly, it does not contain any preservatives!
Keep in mind:
- always use high-quality cocoa powder. The higher the quality of the cocoa, the better the flavor of your frosting.
- Instead of using a whisk with your stand or hand mixer, use the beaters. It will result in a fluffy and creamy frosting that lightens in color the longer you mix it.
- You can use the frosting right away or store it inside an airtight container in a fridge. In that case, you will need to re-blend it for a few seconds with a mixer prior to using it.
Chocolate – Chocolate Birthday Cake
Course: DessertDifficulty: Advanced30
minutes40
minutes6
hoursMoist and fluffy chocolate sponge cake, with rich, velvety chocolate buttercream frosting.
Ingredients
- For sponge cake Ø 18 cm or 7 inch
4 eggs
120 g fine sugar
70 g cake flour (alternatively all-purpose flour)
25 g of dark cocoa powder
- For sponge cake Ø 20 cm or 8 inch
5 eggs
150 g fine sugar
85 g cake flour (alternatively all-purpose flour)
30 g dark cocoa powder
- For a sponge cake Ø 23/24 cm or 9 inch
7 eggs
200 g fine sugar
120 g cake flour (alternatively all-purpose flour)
45 g dark cocoa powder
- for the chocolate buttercream frosting (1 portion)
1/3 cup / 80 ml whole milk
2 1/3 cups 420 g confectioners’ sugar
6 tablespoons / 85 g butter, softened
1/4 teaspoon salt
2 tablespoons vanilla extract
Method
- Prepare the sponge cake
- Take eggs out of the refrigerator 3 hours prior to baking. Gather and measure all other ingredients. Separate egg whites and egg yolks. Mix and sift flour and cocoa into a mixing bowl. Line the bottom of the spring form with parchment paper. Don’t butter or otherwise grease the baking mold. Preheat the oven to 165C / 329F. Position the rack in the middle of the oven.
- Using a stand or hand mixer fitted with a whisk beat the egg whites with a pinch of salt on the highest speed, until soft peeks form, about 2 minutes.
- As the mixer runs on high speed, start adding sugar, spoon by spoon, beating well between each addition. One by one add the egg yolks. Continue beating until light an fluffy.
- Using a spatula or a hand whisk, very gently fold in the flour – cocoa mixture, in two portions, into the egg mixture. Make sure not to stir too much and too long, in order not to destroy the air bubbles, which are very important for the fluffiness of the sponge cake.
- Transfer batter into the prepared baking form and bake for 40 – 45. Make the toothpick test before removing from the oven.
- Leave the cake in the baking form until it has completely cooled down (best, if overnight). Run a knife around the edge of the baking form and gently remove cake from the pan.
- Prepare chocolate buttercream frosting
- In a mixing bowl, whip butter until smooth, about 1 minute.
- Add cocoa powder and confectioners’ sugar and beat until combined. As the mixer runs on low speed, gradually pour in vanilla extract, milk and salt (in that particular order). Continue beating until all ingredients are combined into a smooth and fluffy cream, about 2 minutes, scraping down the sides, if necessary.
- Increase the mixer’s speed to high and whip the frosting for 2 more minutes. You can use the frosting right away or store it inside an airtight container in a fridge. If you refrigerate the frosting, you will need to re-blend it for a few seconds with a mixer prior to using it.
Notes
- After removing the sponge cake from the mold, it is worth turning it upside down. A chocolate sponge cake is rarely perfectly flat. Unlike a white sponge cake, it grows with a minimal hill. Turning it up side down will even out the surface.
