Preheat the oven to 180°C (350°F) and prepare a baking sheet lined with parchment paper.
Whisk eggs and powdered sugar until fluffy.
Fold in almond flour and all-purpose flour gently.
Add melted butter and mix until combined.
Pour the batter onto the prepared baking sheet and spread evenly.
Bake for 12-15 minutes until golden and springy.
Let the sponge cool completely before cutting into layers.
For the coffee buttercream, beat softened butter and powdered sugar until light.
Add brewed coffee gradually, mixing until smooth.
Prepare the ganache by heating cream and pouring it over chopped chocolate; stir until glossy.
Assemble the cake by layering sponge, buttercream, and ganache, then chill for at least 2 hours before serving.