Preheat your oven to 350°F. Grease and flour two 9-inch round cake pans.
In a mixing bowl, whisk together the eggs and sugar until creamy.
Gradually mix in the melted butter and vanilla extract.
In a separate bowl, combine flour, baking powder, and cocoa powder. Mix into the wet ingredients until just combined.
Pour the batter evenly into the prepared pans and bake for 25 minutes. Let cool.
For the filling, heat milk in a saucepan. In a bowl, whisk egg yolks, sugar, and cornstarch. Once the milk is steaming, slowly pour it into the egg mixture. Return to heat and stir until thickened.
Remove from heat, stir in vanilla extract, and let it cool before layering.
Slice the cakes in half horizontally, and fill with pastry cream. Top with the other halves.
Whip the heavy cream until stiff peaks form and spread over the top layer. Enjoy!
Notes
Add fresh fruit on top for a colorful presentation. Enjoy with coffee or tea!