Preheat your oven to 350°F (175°C). Grease three 8-inch round cake pans with vegetable oil and line the bottoms with parchment paper.

In a large mixing bowl, whisk together the all-purpose flour, unsweetened cocoa powder, granulated sugar, baking powder, baking soda, and salt.

Add the large eggs, whole milk, vegetable oil, and vanilla extract to the dry ingredients. Mix until smooth.

Carefully stir in the hot coffee into the batter.

Divide the batter evenly among the prepared cake pans and bake for 25-30 minutes.

Allow the cakes to cool in the pans for about 10 minutes, then transfer to wire racks to cool completely.

Whisk together the sugar, cornstarch, and egg yolks in a saucepan. Gradually stir in the orange juice and cook until thickened.

Heat the heavy cream in a saucepan until steaming. Pour it over the chopped dark chocolate and stir until smooth.

Assemble the cake by placing one layer on a plate, spreading some orange cream filling on top, and repeating with the second layer. Pour ganache over the top.

Garnish with orange slices or candied peel if desired.