This super-rich dessert contains chocolate whipped cream between layers of bittersweet chocolate cake topped with a fudgy chocolate glaze. It’s best made one day ahead and refrigerated overnight. CAKE 1/2 pound bittersweet chocolate, cut into 1/2-inch pieces 2 teaspoons instant espresso powder dissolved in 1/3 cup hot water 6 large eggs, separated 2/3 cup sugar…