5 oz, unsalted butter, at room temperature
1 cup confectioner’s sugar
2 tsp. vanilla sugar
6 eggs, separated
1/2 cup sugar
1 1/4 cups cake flour, sifted
5 oz. semisweet chocolate, melted, cooled
16 oz. apricot jam
8 oz. semisweet chocolate
3/4 cup heavy cream
2 Tbsp. unsalted butter, softened
Lightly butter and line a 9-inch cake pan with parchment paper. Dust lightly with flour.
Preheat oven to 350°F.
Cream together butter and confectioner’s sugar. Add egg yolks, one at a time, and beat until thick. Mix in the melted and cooled chocolate. Beat egg whites with salt until foamy, slowly add the sugar and beat until stiff peaks form, but they are not too dry. Add 1/4 of the egg whites to the chocolate mixture, gently fold it in to lighten up and then fold in the rest of the whites until you can still see some of the whites. Add in cake flour in two additions, be very careful not to over mix.
Pour into prepared cake pan and bake 45-50 minutes, until a cake tester comes out clean. Cool cake for 10 minutes, run a knife around the edge of the pan and invert cake onto a cooling rack. Remove parchment paper and let cool.
Cut cooled cake in half, horizontally, heat jam with 1 tablespoon of water, spread some jam on the bottom layer and tope with second layer. Cover cake with jam and refrigerate.
Melt chocolate glaze in a heatproof bowl over simmering water. Heat cream until it starts to bubble on the edge, pour over chocolate, add butter and stir until smooth. Cool to room temperature and cover cake. Chill until chocolate has set. Serve with whipped cream.