220 g dark chocolate
200 g sugar
1/2 cup cocoa powder
1/3 cup warm water
1 tbsp instant coffee
1 tsp. vanillin
1 tsp. salt
for the mousse:
400 ml heavy cream
165g white chocolate
3 tbsp butter
3 tbsp. baking powder
2 tbsp sugar
1 tsp. vanilla
Melt butter, chop chocolate into pieces, stir until smooth, brew instant coffee with vanilla and salt in warm water, mix with the butter-chocolate mixture, turn on the oven to preheat to 175 degrees.
Beat sugar and eggs until doubled in volume (about 5 minutes), pour in cocoa, mix until smooth, mix with coffee and chocolate mixture.
Pour the batter obtained for the base into a mold, send to the oven, and bake for about 50 minutes.
Prepare the mousse to fill the cake by mixing the butter with the baking powder and pieces of white chocolate, melt the mixture in the microwave for 30 seconds (stir a couple of times).
Whisk the sugar with the egg yolks, put the cooker in a water bath for about 5 minutes until the mixture thickens, remove from the heat, add the vanilla and the butter and white chocolate mixture, pour 2 tbsp. of cream, stir well, and cool.
Whip the cream (1.5 cups) into a stiff foam, add a third of it to the chocolate mixture, stir, add the rest and stir again.
Pour the mousse over the cooled cake base and chill for an hour. Take the white chocolate mousse truffle cake out of the fridge and decorate with a sprinkling of cocoa powder.