Chocolate cream filling:

Cup of Yum
1. Start one day in advance by making the filling.
2. Ganache: Chop the chocolate very finely. Pour the heavy cream into a small pot, carefully bring to a boil, take off the heat, and add the chocolate to the cream. Stir slowly until the chocolate has melted. Place a piece of plastic foil directly over the chocolate cream (so that it doesn't form a "skin"), let the mixture cool completely, then place it in the fridge until the next day.100 g milk chocolate/ 3.5 oz + 100 g dark chocolate 70 - 75 % cocoa/ 3.5 oz + 500 ml heavy cream/ 2 cups

Chocolate cake:

1. You could bake the cakes one day in advance as well. Let them cool completely, then wrap them tightly in plastic foil to prevent them from drying out.
2. Preheat the oven to 350°F/ 180°C. Butter and flour 2 springforms or cake pans of 20 cm/8-inch diameter. Brew one cup of strong coffee.
3. Dry ingredients: In a large bowl, mix and sift the flour, sugar, cocoa powder, baking soda, baking powder, and salt.210 g all-purpose flour/ 1¾ cups + 400 g granulated sugar/ 2 cups + 85 g unsweetened cocoa powder/ ¾ cup + 2 teaspoons baking soda + 1 teaspoons baking powder + ½ teaspoon salt
4. Wet ingredients: Combine the buttermilk, oil, eggs, and vanilla extract, preferably in a jug or another bowl. Slowly pour this mixture over the dry ingredients, whisking with an electric mixer at a very low speed.250 ml buttermilk/ 1 cup + 120 ml vegetable oil/ ½ cup + 2 eggs + 1 teaspoon vanilla extract
5. Combine: Add the hot coffee and stir with a spatula very shortly until the ingredients are just combined. Make sure to scrape the bottom of the bowl as well in the process. Divide the mixture into two equal parts (I use the scale to make sure I divide the mixture evenly) and pour it into the two prepared forms.250 ml hot coffee/ 1 cup
6. Bake for about 40-45 minutes until a toothpick inserted in the middle of the cake comes out relatively clean, it can still be a bit wet, but it should not be covered in chocolate. Let cool in the pan for a while, then transfer the cakes to wire racks and let cool completely.

Assemble the chocolate gateau:

1. Cut cakes: When the cakes are completely cooled, cut each one into two equal slices.
2. Whip the chocolate-heavy cream mixture until stiff with the electric mixer like you would typically whisk heavy cream.
3. Assemble the cake: Place one cake layer on a cake platter. Add some of the chocolate cream, then the second cake layer, cream, third cake layer, cream again, last cake layer. Cover the cake with the remaining chocolate cream, you should use about half of it for layering the cake and half of it for covering the whole cake.
4. Decorate the cake to your liking. I used dried strawberries and meringues crushed between my fingers, some chopped pistachios, and some hazelnut brittle.dried strawberries + meringues + chopped pistachios