Ingredients

• 2 cup all-purpose flour
• 0.75 cup unsweetened cocoa powder
• 2 teaspoon baking soda
• 1 teaspoon baking powder
• 1 teaspoon salt
• 2 ounce unsalted butter, softened
• 1.75 cup granulated sugar
• 3 eggs
• 1 teaspoon vanilla extract
• 0.75 cup hot brewed coffee
• 0.5 cup sour cream
• 8 ounce semi-sweet chocolate, chopped
• 0.5 cup heavy cream
• 6 ounce dark chocolate, chopped
• 0.75 cup heavy cream
• 2 tablespoon unsalted butter

Steps

1. Preheat oven to 350°F (175°C). Grease and flour three 8-inch round cake pans, tapping out excess flour.
2. In a small bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt. Set aside.
3. In a large bowl using a stand mixer or hand mixer, beat softened butter and granulated sugar together on medium speed until light and fluffy, about 3 to 4 minutes.
4. Add eggs one at a time to the butter mixture, beating well after each addition. Mix in vanilla extract.
5. Reduce mixer speed to low. Alternate adding the flour mixture and sour cream, beginning and ending with the flour mixture. Mix until just combined, being careful not to overmix.
6. Pour the hot coffee into the batter and stir gently with a whisk until fully combined. The batter will be thin—this is normal.
7. Divide batter evenly among the three prepared pans. Smooth the tops with an offset spatula.
8. Bake for 30 to 32 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs.
9. Remove cakes from oven and cool in pans for 15 minutes.
10. Turn cakes out onto wire cooling racks and cool completely to room temperature, about 1 hour.
11. Make the semi-sweet ganache: Place chopped semi-sweet chocolate in a heatproof bowl. Heat ½ cup heavy cream in a small saucepan over medium-high heat until it begins to steam and small bubbles form around the edges, about 2 minutes.
12. Pour the hot cream over the chopped semi-sweet chocolate. Let sit undisturbed for 2 minutes, then whisk until smooth and glossy. Cool to room temperature, about 10 minutes.
13. Make the dark chocolate ganache: Place chopped dark chocolate and 2 tablespoons butter in a heatproof bowl. Heat ¾ cup heavy cream in a small saucepan over medium-high heat until it begins to steam, about 2 minutes.
14. Pour the hot cream over the dark chocolate and butter. Let sit for 2 minutes, then whisk until smooth. Let cool for 5 minutes—it should be pourable but still warm.
15. Place the first cake layer on a cake plate or serving board. Spread about ⅓ cup of the cooled semi-sweet ganache evenly over the top using an offset spatula.
16. Place the second cake layer on top and spread with another ⅓ cup of semi-sweet ganache.
17. Top with the third cake layer, pressing gently to level.
18. Slowly pour the warm dark chocolate ganache over the top of the cake, letting it cascade down the sides. Spread gently with an offset spatula if needed to achieve an even coating.
19. Refrigerate the cake for at least 30 minutes before serving to allow the ganache to set slightly.