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

In a large bowl, sift 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 and mix until well combined.

Carefully stir in the hot coffee until the batter is smooth. Divide evenly among the prepared pans.

Bake for 25-30 minutes or until a toothpick inserted comes out clean. Allow to cool in pans for 10 minutes before transferring to a wire rack.

Mix the chopped hazelnuts with the caramel sauce to make the hazelnut caramel filling.

Place the first cake layer on a serving plate and spread a layer of hazelnut caramel filling on top. Repeat with the remaining layers.

In a saucepan, heat the heavy cream until it simmers, then remove from heat. Add the chocolate chips and let sit for a minute before stirring until smooth.

Add the unsalted butter and mix until glossy.

Pour the chocolate ganache over the top of the cake, allowing it to drip down the sides.

Decorate with whole hazelnuts, chocolate shavings, and a drizzle of caramel.

Chill the cake for at least 30 minutes before serving.