Preheat your oven to 350°F (180°C) and thoroughly grease two 8-inch round cake pans. Set them aside.

In a large mixing bowl, sift together the flour, granulated sugar, cocoa powder, baking powder, baking soda, and salt. Stir until combined and set aside.

In a separate large bowl or the bowl of a stand mixer, whisk together the eggs, vanilla extract, vegetable oil, sour cream, and milk until smooth. Gradually incorporate the dry ingredients into the wet mixture, mixing until just combined.

Carefully pour in the hot coffee, blending until the batter is smooth and thin. Divide the batter evenly between the prepared pans.

Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean with only a few moist crumbs attached. Allow the cakes to cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.

In the bowl of a stand mixer fitted with the paddle attachment or using a handheld mixer, beat the softened butter and peanut butter on medium speed for about 5 minutes, until light and fluffy.

Gradually sift in the powdered sugar, adding half at a time, and beat for 2 minutes between each addition. Pour in the heavy cream, vanilla extract, and a pinch of salt, and continue mixing for an additional 3 minutes until creamy and smooth.

The frosting can be spread or piped onto the cake. If not using immediately, store in the refrigerator for up to 7 days; bring to room temperature and re-whip before use.

To assemble, place a small dollop of frosting on your serving plate to secure the first cake layer. If necessary, trim the tops of the cakes with a serrated knife or cake leveler to make them flat and even.

Spread approximately 1 cup of peanut butter frosting over the first layer, ensuring it’s evenly spread from edge to edge. Place the second cake layer on top, using the bottom side of the cake for a flatter, more even top.

Apply a thin layer of frosting all around the cake as a crumb coat to seal in any loose crumbs. Use a straight icing spatula for this, then chill the cake for 20-30 minutes to set the crumb coat.

Once chilled, apply the remaining frosting in a thicker layer, smoothing it out as best as possible. For a decorative finish, use a small angled spatula to create swirls on the top of the cake as you rotate it. Chill the cake again for 20 minutes while you prepare the ganache.

Heat the heavy cream in a medium saucepan over medium-low heat until it just begins to simmer. Place the chopped chocolate in a heatproof bowl.

Pour the warmed cream over the chocolate, allowing it to sit for 5 minutes. Gently whisk the mixture until the chocolate is fully melted and the ganache is smooth and glossy. Let it cool slightly.

Drizzle or pour the ganache over the top of the cake, pushing it gently over the edges to create drips. Alternatively, use a squeeze bottle for controlled drips, then spread the remaining ganache on top of the cake. Garnish with roasted peanuts or chocolate chips if desired.

Store any leftovers in the refrigerator for up to 5 days, allowing slices to come to room temperature before serving for the best flavor and texture.