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

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

Add in the eggs, whole milk, vegetable oil, and vanilla extract and mix until smooth using an electric mixer.

Slowly pour in the boiling water and mix gently until the batter is well blended.

Divide the batter among the prepared pans and bake for 30-35 minutes, or until a toothpick comes out clean.

Allow cakes to cool in the pans for 10 minutes before transferring them to wire racks to cool completely.

To prepare the ganache, heat the heavy cream until it simmers, then pour over the chopped dark chocolate and stir until smooth.

Assemble the cake by stacking layers with ganache in between and frosting the top and sides with remaining ganache.