Make the Cake

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment paper.
2. Mix Dry Ingredients: In a medium bowl, whisk together flour, cocoa powder, baking powder, baking soda, and salt.
3. Combine Wet Ingredients: In a large bowl, whisk together the milk, vegetable oil, eggs, and vanilla extract. Add the granulated and brown sugars, and mix until smooth.
4. Add Melted Chocolate: Pour the melted dark chocolate into the wet ingredients and mix until fully combined.
5. Incorporate Dry Ingredients: Gradually add the dry ingredients to the wet mixture, stirring until smooth. Be careful not to overmix.
6. Add Boiling Water: Stir in the boiling water. The batter will be thin, but that’s exactly what you want—it’ll help create the dense, moist texture.
7. Bake: Divide the batter evenly between the two prepared cake pans. Bake for 1 hour to 1 hour 15 minutes, or until a toothpick inserted into the center comes out clean.
8. Cool: Allow the cakes to cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely.

Prepare the Frosting

1. Heat the Cream: In a small saucepan, heat the heavy cream over medium heat until it begins to simmer. Don’t let it boil.
2. Make the Ganache: Pour the hot cream over the chopped dark chocolate in a heatproof bowl. Let it sit for a few minutes to soften the chocolate, then whisk until smooth and glossy.
3. Add Butter: Stir in the butter until fully melted and the ganache is silky smooth. If you prefer a sweeter frosting, you can add powdered sugar to taste.
4. Cool Slightly: Let the ganache cool to room temperature before spreading it on the cake. It should thicken slightly but remain spreadable.

Assemble the Cake

1. Layer the Cakes: Place one cake layer on a serving platter. Spread a generous amount of frosting on top.
2. Top with Second Layer: Place the second cake layer on top, pressing gently to ensure it’s level.
3. Frost the Cake: Spread the ganache over the top and sides of the cake. Use a spatula to create a smooth finish, or get creative with swirls and texture.
4. Chill: Let the cake sit for about 30 minutes to allow the frosting to set before slicing.