1. Preheat the oven to 350°F (180°C). Butter two 8-inch cake pans and line the bottoms with parchment paper; grease the sides and dust with cocoa powder.
2. In a large bowl, combine the flour, cocoa powder, sugar, baking powder, baking soda, and salt.
3. In another bowl, mix together the buttermilk, eggs, oil, and vanilla extract. Add this mixture to the dry ingredients and mix until incorporated. Stir in the hot coffee or water.
4. Divide the batter evenly between the prepared cake pans and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Allow the cakes to cool completely.
Make the Frosting:
1. In a large bowl, beat the butter and peanut butter until fluffy. Gradually add the powdered sugar and heavy cream, then vanilla extract, beating until light and fluffy.
2. Transfer the frosting to a piping bag.
Assemble the Cake:
1. Trim the tops of the cakes to level them if necessary. Place one cake layer flat side down on a plate or cake stand. Spread a layer of frosting on top, then place the second cake layer on top, flat side up.
2. Frost the top and sides of the cake with the peanut butter frosting. Chill the cake in the refrigerator for 2-3 hours.
Make the Ganache:
1. Chop the dark chocolate and place it in a bowl. Heat the heavy cream until it just begins to simmer, then pour it over the chocolate. Let it sit for 1-2 minutes, then stir until smooth.
2. Pour the ganache over the chilled cake, allowing it to drip down the sides. Smooth the top with a spatula.
3. Pipe additional peanut butter frosting decorations on top of the ganache if desired.
Storage:
Store the cake covered in the refrigerator for up to 5 days.
Savor the blissful harmony of chocolate and peanut butter in this masterpiece of confectionary delight, perfect for any occasion that demands a touch of indulgence!
