Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans to prevent sticking.

In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined (about 2 minutes).

Add eggs, milk, vegetable oil, and vanilla extract to the dry ingredients. Beat with a mixer on medium speed for 2-3 minutes until smooth and well mixed.

Gradually add boiling water to the mixture, stirring gently. Mix until the batter is smooth; it will be thin but that’s normal.

Pour the batter evenly into the prepared pans.

Bake in the preheated oven for 30 minutes, or until a toothpick inserted into the center comes out clean.

Remove cakes from oven and cool in the pans for 10 minutes. Then, transfer to wire racks to cool completely.

For the ganache, heat the heavy cream in a small saucepan over medium heat until it just begins to simmer (about 3-4 minutes).

Pour the hot cream over the chopped chocolate in a bowl. Let sit for 2 minutes, then stir until smooth and glossy.

Once the cakes are completely cooled, layer them if desired and pour or spread the ganache over the top and sides.