Vienna's world-famous chocolate torte; a dense, velvety dark chocolate sponge layered with tart apricot jam and enrobed in a mirror-like chocolate ganache glaze.
Sponge: Melt the chocolate gently. Beat the butter and sugar until creamy, then beat in egg yolks one by one. Whisk egg whites to stiff peaks with remaining sugar. Fold melted chocolate, flour, and egg whites together.
Baking: Bake in a 24cm springform tin at 170°C for 50-55 minutes. Cool completely, then slice horizontally into two even sponge rounds.
Assembly: Sandwich the layers with warm apricot jam and coat the outside smoothly with remaining jam.
Glazing: Pour the warm, glossy chocolate glaze over the cake to coat seamlessly. Chill until set, then slice and serve with unsweetened whipped double cream.