By placing white chocolate at center stage of this opera cake, we have had to change the classic opera flavors of coffee and chocolate. But we have retained the exquisite opera texture and created a flavor system that sings: full-bodied white chocolate and sweet honey, with almonds as a back note, are presented in paper-thin layers of cake, buttercream, and mousse

Almond Biscuit
3/4 cup slivered almonds
1/2 cup plus 1 tablespoon granulated sugar, divided
2 large eggs, at room temperature
3 large egg whites, at room temperature
1/4 cup cake flour
2 tablespoons unsalted butter, melted

Sugar Syrup
1/3 cup water
1/4 cup granulated sugar
1/4 cup honey
1 tablespoon B&B liqueur

Honey Buttercream
1 cup (2 sticks) unsalted butter, softened
3 large egg yolks, at room temperature
1/4 cup honey

White Chocolate Mousse
7 ounces Swiss white chocolate, coarsely chopped
1 cup plus 3 tablespoons heavy cream, divided
1 tablespoon B&B liqueur

White Chocolate Glaze
7 ounces Swiss white chocolate, coarsely chopped
1/4 cup heavy cream

Chocolate Decor
1 ounce bittersweet chocolate

Make the almond biscuit

1. Position a rack in the center of the oven and preheat to 400°F. Butter a 17 1/2-by-11 1/2-inch jelly roll pan and line the bottom with parchment paper. Lightly butter and flour the sheet, shaking off the excess flour. Set aside
2. Using a food processor fitted with a metal chopping blade, process the almonds to a very fine cornmeal-like texture. Place the ground almonds in a medium bowl and stir in 1/2 cup of the sugar.
3. Using a handheld  electric mixer, beat 1 whole egg into the almond mixture. Beat the mixture on high speed for 1 minute. Add the second egg and beat on high speed for another minute. Scrape down the sides of the bowl and the beaters. The mixture should be pale yellow in color.
4. Place the egg whites in a 4 1/2-quart bowl of heavy-duty electric mixer fitted with the wire whisk attachment. Beat the whites on high speed until they are frothy. Slowly add the reserved tablespoon of sugar and beat until the whites are slightly glossy and stiff peaks form.
5. Sift the flour over the egg-almond mixture and , using a large rubber spatula, fold in the flour until incorporated. Gently fold in the whites in two batches. Fold in the melted butter, making sure it is completely incorporated into the batter.
6. Pour the mixture onto the prepared pan in an even layer approximately 1/4-inch thick. Tap the pan lightly on the counter and smooth to remove any air pockets.
7. Bake the cake for 10 minutes, or until lightly browned. Remove from the oven and cool on a wire rack for 10 minutes. Invert the cake onto a wire rack, peel off the parchment paper and cool completely. Cut the cake into 3 equal portions, each 5 1/2-inches wide. If the cake will not be assembled until the following day, wrap securely in plastic wrap, placing a piece of waxed paper in between each layer.

Make the sugar syrup
1. In a small heavy saucepan, combine the water, sugar, and honey. Bring to a boil and boil for 2 to 3 minutes, until the sugar is dissolved and the syrup is clear. Remove from heat and add the B&B liqueur, set aside.

Make the honey buttercream

1. Place the butter into a medium bowl and cream, using a handheld electric mixer, until completely softened and smooth, set aside.
2. In a 4 1/2-quart bowl of a heavy-duty electric mixer fitted with wire whisk attachment, beat the yolks on  medium speed until pale yellow in color.
3. Spray a heatproof glass measure or ramekin with nonstick cooking spray. Place the honey in a small saucepan. Stirring constantly, bring the honey to a rolling boil over medium-high heat. Immediately pour the honey into the empty glass measure or ramekin to stop the cooking. Pour half of the honey onto the yolks, turn the mixer to high, beat for 1 minute. Turn off the mixer, add the remaining honey and beat until the bowl feels cool, for about 5 minutes. Scrape down the sides of the bowl well with a rubber spatula. Add the softened butter and beat until completely smooth. Scrape into a small bowl, cover, and reserve.