Separate the eggs for the sponge cake. Beat the egg whites with 1 pinch of salt until stiff, adding 125 g sugar. Stir in the egg yolks one by one. Sift flour and baking powder on top and fold in. Spread the mixture into a springform pan (26 cm Ø) lined at the bottom with baking paper. Bake in the preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer) for about 20 minutes. Let it cool down.
Wash, clean and halve the strawberries. Puree 250 g berries. Soak gelatine in cold water. Cut the sponge twice horizontally. Place the bottom cake layer on a cake plate and place a cake ring around it.
For the cream, mix mascarpone, 75 g sugar and the puree. Squeeze the gelatine, dissolve at low heat. First stir approx. 3 tbsp. cream into the gelatine, then stir everything into the rest of the cream. Whip 300 g cream until stiff and fold in.
Spread the bottom layer with approx. 1⁄3 cream and cover with 350 g strawberries. Lay on the middle base. 1⁄3 Spread cream on top. Cover with upper base. Spread the rest of the cream and strawberries on top. Chill the cake for about 2 hours.
Mix the cake glaze powder, 3 level tablespoons of sugar and 1⁄4 l cold water in a pot. Bring to the boil briefly while stirring. Spread on the strawberries. Refrigerate the cake again for about 1 hour.
Whip 150 g cream until stiff. Remove cake ring. Spread the cake ring with cream. Decorate with wafer hearts if desired.
Stir 100 g icing sugar with approx. 1 tbsp. milk and a little red food colouring until smooth. Pour the icing into a small freezer bag, cut off a small corner. Decorate 1 pack (16 pieces) of wafer hearts with it, let it dry. Stick them to the edge of the cake.