2 eggs
225 ml sugar
225 ml all-purpose flour
1 tablespoon cocoa powder
1⁄2 teaspoon baking soda
1⁄2 teaspoon salt
1 teaspoon vanilla sugar (or extract)
300 g sour cream
Cognac syrup
115 ml water
3 tablespoons sugar
1 tablespoon cognac
Filling
300 g butter
1 (400 g) can sweetened condensed milk, plus
1 tablespoon cocoa powder (or use sweetened condensed chocolate milk)
Frosting
150 g semisweet chocolate
30 g butter
6 tablespoons heavy cream
5 tablespoons powdered sugar
3 tablespoons cocoa powder (optional)