Raspberry foam cake
Wild raspberries have been gathered for consumption by humans for thousands of years. Hybridization has enabled their cultivation, and the raspberry cultivars have spread and are widely grown in all temperate regions of the world. Due to their sweet juicy taste and antioxidant power, raspberries are one of the world’s most consumed berries. Not only do they taste great but they’re good for you as well. They are an excellent source of vitamin C, A, B1 and B2; they are a low-glycemic index food, with total sugar content of only 4% and no starch.
Raspberries have a short shelf life, you can store them in the fridge only for 2-3 days, but as an alternative you can also freeze them. The secret to successful freezing is to use unwashed and completely dry berries that should be placed in a single layer on a cookie sheet in the freezer. Once the berries are frozen, transfer them to plastic bags or freezer containers.
Raspberries can be used up not only in desserts and cakes, but amazing jams and syrups can be made from them, too. In the following recipe a cocoa sponge cake is spread with a raspberry-yogurt-whipped cream filling and decorated with melted chocolate.
For the sponge cake:
- 4 eggs
- 3 tbsp flour
- 3 tbsp sugar
- 1 tbsp cocoa powder
- 2 tsp baking powder
For the cream filling:
- 500 g (~1 lb) raspberries
- 450 g (~2 cups) yogurt
- 400 g (~1 2/3 cups) whipping cream
- 140 g (~1 cup) powdered sugar
- 40 g (~1 1/2 oz) gelatine
- 100 ml (~1/2 cup) water
For the chocolate glaze:
- 50 g (~1 3/4 oz) semi-sweet dark chocolate
- 15 g (~1 tbsp) butter
Line a 20×30 cm / 8×12 inch baking pan with parchment paper. Preheat the oven to 180°C.
In a small bowl combine flour, cocoa and baking powder. In a mixing bowl whip the egg whites until stiff. In another bowl beat the egg yolks with sugar until its color turns pale. Gradually stir in the dry ingredients, then gently fold in the egg whites. Pour the batter into the prepared baking pan and bake for about 20 minutes or until a cake tester comes out clean. Transfer the sponge cake onto a wire rack and cool completely.
Puree the raspberries with a hand blender. Add yogurt and powdered sugar and stir until well combined. Whip the cream to stiff peaks and set aside. Place gelatine and a half cup of water in a saucepan and heat until gelatine dissolves completely. Don’t boil it! Remove from the heat and cool to room temperature. In a fine stream pour the gelatine into the raspberry-yogurt mixture while whisking continuously, then gently fold in the whipped cream.
Place the sponge cake in a clean baking pan and pour the filling onto its top. Chill until the cream sets – it takes about 4-5 hours. Melt chocolate and butter, spoon the glaze in a piping bag or a zip bag, and decorate the top of the cake. Put the cake in the fridge for an hour before serving.