Preparing the Joconde Sponge

1. Preheat oven to 220°C (425°F). Line a 40x30cm baking sheet with parchment paper and lightly butter.
2. Using a stand mixer with paddle attachment, combine almond flour, powdered sugar, all-purpose flour, and whole eggs. Mix until smooth and pale, about 3 minutes.
3. In a separate clean bowl, whisk egg whites to soft peaks. Gradually add granulated sugar, continuing to whisk until glossy, firm peaks form.
4. Fold one-third of the meringue into the almond mixture to lighten it. Gently fold in remaining meringue in two additions, preserving as much volume as possible.
5. Drizzle melted butter around the bowl’s edge and fold in with minimal strokes. Pour onto prepared baking sheet and spread evenly with offset spatula.
6. Bake 8-10 minutes until golden and springs back lightly when touched. Cool completely on the pan.

Creating the Coffee Syrup

1. Dissolve espresso powder in hot water. In a small saucepan, combine sugar with remaining water and bring to boil, stirring until sugar dissolves.
2. Remove from heat, stir in dissolved espresso and cognac. Cool completely before using.

Making French Coffee Buttercream

1. Dissolve espresso powder in hot water; set aside.
2. In a heavy saucepan, combine sugar and water. Bring to boil without stirring, washing down crystals with wet pastry brush. Cook to 118°C (245°F) on candy thermometer.
3. Meanwhile, whisk egg yolks in stand mixer bowl until pale.
4. With mixer running on medium speed, slowly pour hot syrup into yolks, avoiding whisk and bowl sides. Add espresso mixture and continue beating until mixture cools to room temperature, about 10 minutes.
5. Switch to paddle attachment. With mixer on medium speed, add butter pieces one at a time. Mixture may look curdled initially—continue beating until smooth and glossy, about 5-8 minutes.

Preparing Chocolate Elements

For Ganache:

1. Melt chocolate and butter together in double boiler or microwave, stirring until smooth. Cool to spreading consistency.

For Glaze:

1. Melt chocolate, butter, and corn syrup together, stirring until smooth. Add cognac if using. Cool to 85°F before using.

Assembly Process

1. Cut Joconde into three equal rectangles. Place first layer on serving plate or cake board.
2. Brush generously with coffee syrup. Spread with half the buttercream, smoothing with offset spatula.
3. Add second sponge layer, brush with syrup, then spread with all chocolate ganache.
4. Top with final sponge layer, brush with remaining syrup, then spread with remaining buttercream, creating perfectly smooth surface.
5. Refrigerate 30 minutes until buttercream firms.
6. Pour chocolate glaze over cake, spreading quickly to edges for smooth finish. Refrigerate until set, about 1 hour.
7. Trim edges with sharp knife for clean presentation. Cut into individual portions using sawing motion with thin, sharp knife.