Chocolate Hazelnut Cake with Chocolate Filling and Hazelnut Buttercream

This elaborate cake shows you how to use two kinds of cake layers, a moist chocolate sponge cake, cut into layers, and disks of dacquoise, along with two kinds of fillings, whipped chocolate ganache and hazelnut buttercream, to assemble a finished cake. You can simplify the recipe by doubling the amounts of one component—cake or filling—and eliminating another.

When making such an elaborate cake, a cake stand is helpful in two ways. First, it allows you to place the ca