Preheat your oven to 350°F (175°C) and prepare two 9-inch round cake pans by greasing and dusting with flour.

In a large mixing bowl, combine the dry ingredients: flour, sugar, cocoa powder, baking powder, baking soda, and salt. Mix well.

Add the wet ingredients: eggs, milk, vegetable oil, and vanilla extract. Beat on medium speed for about 2 minutes until smooth.

Carefully stir in the boiling water until well combined.

Pour the batter evenly into the prepared pans and bake for 30-35 minutes. Check for doneness with a toothpick.

While the cakes cool, heat the heavy cream in a saucepan until it simmers. Pour it over the chopped chocolate and let it sit for 5 minutes.

Stir in the butter until the ganache is smooth and glossy.

Once the cakes are cool, layer one on a serving plate, spread ganache on top, and place the second layer on top. Pour remaining ganache over the cake.

Slice and serve at room temperature, optionally with ice cream or whipped cream.