Creamy Coffee and Cognac Cake

Butter springform pan.

For the batter: dissolve coffee powder in 2 tablespoons of hot water. Separate eggs. Whisk egg yolks with coffee, 100 grams (approximately 3 1/2 ounces) of sugar and vanilla sugar until frothy. Beat egg whites with remaining sugar until stiff. Fold egg whites into egg tolks. Combine flour, baking soda and cornstarch and fold into egg mixture. Pour batter into prepared pan and smooth. Bake in preheated oven at 180°C (approximately 350°F) for about 45 minutes (inserted toothpick should come out clean). Remove cake from the oven, allow to cool briefly and invert onto a wire rack. Let stand overnight.

Cut cake twice horizontally. Dissolve coffee powder in 75 ml (approximately 11/3 cup) of water, mix with powdered sugar and drizzle all cake layers with the mixture.  

For the cream: soften gelatine in cold water. Whisk mascarpone with quark and powdered sugar until smooth. Dissolve gelatin with cognac in a small saucepan on low heat. Add 3-4 tablespoons of cream and mix well, combine with the rest of cream. Beat heavy cream until stiff and fold into mixture. Fill approximately 1/5 of cream into a piping bag with a plain nozzle. Spread each cake layer with cream and stack them together. Coat cake with remaining cream on all sides and decorate with cream dollops on top. Refrigerate for at least 3 hours.