For the Brownie Layers:
8 large eggs
3 cups sugar
16 ounces /4 sticks melted butter / 450 grams
2 cups cocoa, sifted
1 teaspoon vanilla extract
2½ cups flour, sifted
½ teaspoon kosher salt
1 teaspoon baking powder
For the Coconut Filling:
1 cup walnuts, measure then finely grind in the food processor
1 cup unsweetened coconut flakes
½ cup heavy cream
½ cup sugar
1 egg yolk
3 tbsp. butter, room tempreture
For the Vanilla Buttercream:
3 sticks of butter, softened
8 oz mascarpone cheese, chilled
2½ cups powdered sugar
1 vanilla bean
pinch of salt
For the Chocolate Ganache:
8 ounces semisweet chocolate, chopped
2 tbsp. light corn syrup
3 tablespoons unsalted butter
1 cup heavy cream
Preheat oven to 350°F.
Spray with baking spray or grease with butter the bottom of 3 8inch round pans, place parchment paper on the bottom and spray with baking spray again.
In the bowl of an electric mixer, whisk together melted butter and sugar until smooth. Add vanilla extract and each egg one at a time on low speed and whisk until well combined.
Using a large rubber spatula, gently stir in flour, cocoa, baking powder and salt.
Spread batter equally into the pans and bake for 25-30 minutes until set.
Remove from oven and let cool completely into the pans before assembling the cake.
Run a knife thru the sides of the pans to release the brownie layers. Carefully, cover one pan with a cake lifter, and flip the brownie layer onto the cake lifter. Place on the counter and repeat with the remaining brownie payers.
For the Coconut Filling:
Place butter, walnuts and coconut in a large bowl and set aside.
In a medium sauce pan, on low/medium heat, stir together the heavy cream, sugar and egg yolk until the mixture begins to thicken and coats the back of a spoon (180 degrees F.). Pour the hot custard immediately onto the walnut-coconut mixture and stir until the butter is melted. Cool completely to room temperature before topping the brownie layers.
For the Vanilla Mascarpone Buttercream:
Place softened butter and mascarpone into the bowl of an electric stand mixer that has been fitted with the wire attachment. Turn the mixer on a medium setting and cream until smooth and combined, 2 - 3 minutes.
Add sugar, ½ a cup at a time. Add vanilla bean seeds and a pinch of salt and whisk until well-incorporated.
If the frosting is too thick add heavy cream one tablespoon at a time until it has reached the desired consistency.
Pour the chocolate ganache on top of the cake, distribute evenly and also ice the sides of the cake while the ganache is dripping down.
Decorate with frosting if you have any remaining and chocolate sprinkles.
Chill the cake for at least 2 hours before serving.