Lightly mix the egg whites and add sugar to them - mix on high speed until the egg whites are very fluffy, white and thick.
4 egg whites, 200 g sugar
Meanwhile, sift both flours and cocoa together through a sieve.
70 g wheat flour - all-purpose, 70 g potato starch, 20 g dark cocoa
Add the egg yolks to the egg whites and gently mix or blend on low speed.
4 egg yolks
Add the flour and gently mix.
Pour the batter into the springform pan (baking paper on the bottom, and clean, dry sides).
Bake the chocolate sponge cake in an oven preheated to 170 degrees (convection) for about 40 minutes - until a dry skewer comes out clean.
Cool the sponge cake well and cut it into two layers.
How to make chocolate mousses for the cake.
Chop the chocolates and transfer them to separate bowls.
200 g white chocolate, 100 g dark chocolate
Mix the egg yolks with a mixer on high speed.
4 egg yolks
Heat the heavy cream and when hot, slowly pour into the egg yolks, continuously mixing on low speed.
250 ml heavy cream
Pour the mixture back into the saucepan and heat over low heat until the cream slightly thickens.
Pour roughly half of the cream into each of the chocolates, wait 1-2 minutes, and mix thoroughly until the chocolates are well dissolved. Leave to cool slightly.
Whip the cold heavy cream with a mixer on high speed until thick.
250 ml heavy cream
Add half to each of the melted chocolates and gently mix.
Chocolate Tuxedo cake assembly
Place the bottom sponge cake layer back in the springform pan and soak it - you can use coffee like me, or sweetened tea or lightly sweetened water.
2 teaspoons instant coffee, 1 teaspoon sugar, approx 200 ml hot water, approx 30 ml amaretto
Spread the dark chocolate mousse over the sponge cake.
Carefully spread the white chocolate mousse and gently distribute it.
Cover the mousse with the second sponge cake layer and soak it.
Chill the cake in the refrigerator for at least 4 hours - so that the mousses set.
Before serving, pour chocolate glaze over the cake - heat the heavy cream in a saucepan, when hot add the chopped chocolate and mix thoroughly. Let the glaze cool slightly and pour it over the top of the cake.
50 ml heavy cream, 100 g milk chocolate
Decorate the cake as desired.
Film
Uwagi
The recipe video is in Polish, but you can watch it to see the step-by-step process.