Ingredients
Method
Preparation of the Joconde Sponge
- Preheat your oven to 425°F (220°C). Line two 15×10-inch jelly roll pans with parchment paper and lightly grease.
- Beat egg whites in a clean bowl until foamy, gradually adding 2 tablespoons of sugar until soft peaks form.
- In a separate large bowl, mix almond flour and powdered sugar, then beat in whole eggs until light and fluffy, about 3 minutes.
- Gently fold in flour, followed by melted butter, and then fold in whipped egg whites in three additions, being careful not to deflate the batter.
- Divide the batter between prepared pans, spreading evenly. Bake for 5-7 minutes until golden and springy.
Making the Coffee Syrup
- Combine coffee and sugar in a saucepan over medium heat, stirring until the sugar dissolves.
- Bring to a simmer for 1 minute, remove from heat, add coffee liqueur (if using), and let cool completely.
Preparing the Coffee Buttercream
- Combine sugar and water in a saucepan over medium heat and cook until it reaches 240°F (115°C) on a candy thermometer.
- Beat egg yolks in a stand mixer until pale and thick, then slowly pour hot syrup down the side of the bowl and beat until cool.
- Gradually add softened butter one tablespoon at a time until fully incorporated, then add dissolved espresso and vanilla, beating until smooth.
Creating the Banana Ganache
- Place chopped chocolate in a heat-resistant bowl. Bring heavy cream to a simmer, then pour over chocolate.
- Let stand for 1 minute, stir until smooth, then fold in banana puree and butter until fully incorporated.
- Allow to cool until spreadable but not firm, about 20-30 minutes.
Assembling the Cake Layers
- Cut each sponge sheet into three equal rectangles, giving you six layers total.
- Layer on a serving plate, brushing generously with coffee syrup and spreading a thin layer of coffee buttercream.
- Alternate sponge and filling layers, ensuring each sponge is brushed with syrup. Finish with a sponge layer on top.
- Refrigerate for 30 minutes to set before glazing.
Preparing and Applying the Chocolate Glaze
- Place chocolate in a bowl and heat cream until simmering, then pour over chocolate.
- Add corn syrup and butter, let stand for 1 minute, then stir until smooth and glossy. Cool slightly until pourable.
- Place the chilled cake on a wire rack and pour the glaze evenly over the top.
Finishing Touches
- Once the glaze has set, trim edges with a hot knife for clean lines.
- Garnish with chocolate curls, gold leaf, or sliced bananas just before serving.
Nutrition
Notes
For optimal flavor, serve at cool room temperature about 20 minutes after removing from refrigeration. Can be modified for lighter versions by reducing sugar and substituting ingredients.
