Opera Cake

The Opera Cake is a French cake. It is made with layers of sponge cake soaked in coffee syrup, layered with ganache and coffee buttercream and covered in a chocolate glaze.The top looks like a top of a choclate bar.

Ingredients
&nbsp For almond sponge cake
 * 3 tablespoons cake flour (not self-rising), sifted after measuring, plus additional for dusting pan
 * 2 whole large eggs at room temperature for 30 minutes
 * 1 cup almond flour (3 1/2 oz) or 2/3 cup blanched whole almonds (see cooks' note, below)
 * 1/2 cup confectioners sugar, sifted after measuring
 * 2 large egg whites at room temperature for 30 minutes
 * 1/8 teaspoon cream of tartar
 * 1/8 teaspoon salt
 * 1 tablespoon granulated sugar
 * 2 tablespoons unsalted butter, melted, foam discarded, and butter cooled

For coffee syrup
 * 1 teaspoon instant-espresso powder
 * 1/2 cup plus 1 tablespoon water
 * 1/2 cup granulated sugar
 * 1/4 cup Cognac or other brandy

For coffee buttercream
 * 2 teaspoons instant-espresso powder
 * 1/4 cup plus 1 tablespoon water
 * 6 tablespoons granulated sugar
 * 2 large egg yolks
 * 1 stick (1/2 cup) unsalted butter, cut into 1/2-inch cubes and softened

For chocolate glaze Special equipment: a 15- by 10-inch shallow baking pan; an offset metal spatula; a candy thermometer; a small sealable plastic bag 
 * 3/4 stick (6 tablespoons) unsalted butter
 * 7 oz fine-quality bittersweet chocolate (not unsweetened; preferably 70 to 71% cacao), coarsely chopped