Step 1

Preheat the oven to 350 degrees Fahrenheit. Grease and flour two 9-inch round cake pans, tapping out the excess flour. Alternatively, grease the tins with cooking spray and line the bottoms with parchment paper.

Step 2

In a medium saucepan, whisk 5 tablespoons of flour with 1 cup of whole milk (for the frosting) over medium heat. Cook, stirring constantly, until the mixture thickens into a paste - about 5-7 minutes. Transfer the paste to a shallow bowl, cover it with plastic (press it down so it touches the surface), and leave to cool. (For the best results, place in the fridge overnight.)

Step 3

In a large mixing bowl, stir the flour, sugar, cocoa powder, baking soda, baking powder, and salt until well combined.

Step 4

In a separate bowl, gently whisk the eggs, buttermilk, coffee, oil, and vanilla. Pour the wet ingredients into the flour bowl and beat with an electric mixer on medium speed for 2 minutes. (The batter will be thin.)

Step 5

Divide the batter evenly between the prepared pans and bake for 30 to 35 minutes or until a toothpick inserted into the center comes out clean.

Step 6

Cool in the pans for 10 minutes, then invert onto wire racks to cool completely.

Step 7

While the cakes cool, place the cooled flour paste into a large bowl. Beat until smooth, then add the vanilla extract, softened butter and granulated sugar. Beat on high speed until the filling is smooth and resembles whipped cream. Set aside.

Step 8

Warm the heavy cream in a medium saucepan over medium-low heat until it just begins to simmer. Stir frequently so the bottom doesn’t cook - do not boil.

Step 9

Place the chopped chocolate in a large, heat-proof bowl. Pour the hot cream over the chocolate, let it sit for a few minutes, then stir until smooth and glossy. Set aside to cool - it should be thick but pourable.

Step 10

When the cakes are cool, use a serrated knife to cut off the dome so they're both flat. Then, spread all of the Ermine filling over the top of one cake. Gently place the second cake layer on top.

Step 11

Pour the cooled ganache over the assembled cake, using a spatula to spread it over the top and sides.

Step 12

Place the cake in the fridge for at least 1 hour. Then, slice, serve, and enjoy.