Opéra Cake

Step 1

Preheat oven to 375°F. Line a 9×13-inch baking sheet with parchment paper.

Step 2

Whisk almond flour and powdered sugar together in a large bowl.

Step 3

Separate 3 eggs; add 3 whole eggs + 2 yolks to almond mixture, whisk until smooth.

Step 4

Sift flour over the batter; fold in gently until no streaks remain.

Step 5

Fold melted butter into batter in two additions until fully incorporated.

Step 6

Whip 3 egg whites in a separate bowl until stiff peaks form, ~3 minutes.

Step 7

Fold egg whites into batter in two additions until no white streaks remain.

Step 8

Spread batter evenly onto prepared pan. Bake until a toothpick comes out clean, ~18 minutes.

Step 9

Cool cake on rack for 10 minutes, then turn out onto a wire rack to cool completely.

Step 10

Stir espresso powder into 0.25 cup hot water until dissolved. Add 1 tablespoon sugar; cool.

Step 11

Place chopped chocolate in a heatproof bowl. Heat 0.25 cup water until steaming.

Step 12

Pour hot water over chocolate; let sit 2 minutes, then stir until silky and smooth.

Step 13

Beat softened butter with remaining instant espresso and 2 tablespoons espresso syrup until fluffy, ~4 minutes.

Step 14

Trim cooled cake edges; cut into three equal rectangles.

Step 15

Brush each cake layer with remaining coffee syrup until visibly moist.

Step 16

Spread half the buttercream over first cake layer; place second cake on top.

Step 17

Spread remaining buttercream over second layer; top with third cake layer.

Step 18

Pour slightly cooled ganache over the cake; let it set at room temp for 15 minutes.

Step 19

Refrigerate at least 2 hours before serving. Slice with a hot, wet knife.