Step 1: Prepare Pans and Preheat
Preheat your oven to 350°F (175°C). Grease two 9-inch round cake pans with butter or cooking spray, line the bottoms with parchment paper circles, then grease the parchment. Lightly dust with cocoa powder, tapping out excess. This ensures easy cake release.

Step 2: Mix Dry Ingredients
In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt. Whisk for at least 30 seconds to ensure everything is evenly distributed and the cocoa has no lumps.

Step 3: Combine Wet Ingredients
In a separate large bowl, whisk together the eggs, buttermilk, oil, and vanilla extract until well combined and slightly frothy.

Step 4: Make the Batter
Pour the wet ingredients into the dry ingredients and whisk until just combined. The batter will be thick. Now, carefully stir in the hot coffee. The batter will become very thin—this is normal and correct! Don’t panic. This thin batter is what creates the incredibly moist cake texture.

Step 5: Bake the Cakes
Divide the batter evenly between your prepared pans (they’ll be about halfway full). Bake for 28-32 minutes, or until a toothpick inserted in the center comes out with just a few moist crumbs (not wet batter). The tops should spring back when lightly touched.

Step 6: Cool Completely
Remove cakes from oven and let them cool in the pans on wire racks for 10 minutes. Then, carefully run a knife around the edges and invert the cakes onto the racks. Remove the parchment paper and let cool completely, about 1 hour. Do not attempt to frost warm cakes—they’ll fall apart and melt your frosting.

Step 7: Make Peanut Butter Buttercream
In a large bowl using an electric mixer, beat the peanut butter and softened butter together on medium speed for 2-3 minutes until creamy and well combined. Reduce speed to low and gradually add the powdered sugar, 1 cup at a time, beating until combined. Add the heavy cream, vanilla, and salt. Increase speed to medium-high and beat for 3-4 minutes until light, fluffy, and spreadable. If too thick, add more cream 1 tablespoon at a time. If too thin, add more powdered sugar.

Step 8: Assemble the Cake Layers
Place one completely cooled cake layer on your serving plate or cake stand. If the top is domed, use a serrated knife to level it for easier stacking. Spread about 1½ cups of peanut butter buttercream evenly over the top, leaving a small border around the edge (the weight of the second layer will push it out slightly). Place the second cake layer on top, bottom side up for a flat top. Apply a thin “crumb coat” of frosting all over the cake—this is a thin layer that seals in crumbs. Refrigerate for 15 minutes to set.

Step 9: Final Frosting
After the crumb coat has set, spread the remaining peanut butter buttercream generously over the top and sides of the cake, using an offset spatula to create a smooth finish. You can make it perfectly smooth or leave it slightly textured—both look beautiful.

Step 10: Make Chocolate Ganache
Place chocolate chips in a heatproof bowl. In a small saucepan, heat the heavy cream until it just begins to simmer (don’t boil). Pour the hot cream over the chocolate and let sit undisturbed for 2 minutes, then whisk until smooth and glossy. Let cool for 5-10 minutes until slightly thickened but still pourable.

Step 11: Create Ganache Drips
Transfer ganache to a piping bag or squeeze bottle (or carefully pour from a spoon). Working around the top edge of the cake, create drips by letting ganache slowly drip down the sides. You can make short drips or long dramatic ones—it’s your choice. Once you’ve gone around the edge, pour remaining ganache on top and spread it to the edges with an offset spatula.

Step 12: Decorate and Serve
While the ganache is still slightly soft, add your decorations on top—chopped Reese’s cups, Reese’s Pieces, chopped peanuts, or chocolate shavings. Refrigerate the cake for 30 minutes to set the ganache, then bring to room temperature 30 minutes before serving for the best flavor and texture.