Preparation:

Step 1: Prepare the Cake Batter

1. Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans or line them with parchment paper.
2. In a large mixing bowl, sift together the flour, sugar, cocoa powder, baking powder, baking soda, and salt. Whisk to combine evenly.
3. Add the buttermilk, vegetable oil, eggs, and vanilla extract to the dry ingredients. Mix until smooth and lump-free using a hand or stand mixer.
4. Gradually stir in the boiling water, a little at a time, to avoid splashes. The batter will become thin, which is normal for achieving moist cake layers.

Step 2: Bake the Cake Layers

5. Divide the batter evenly between the prepared pans. Tap the pans gently on the counter to release any air bubbles.
6. Bake in the preheated oven for 30–35 minutes or until a toothpick inserted in the center comes out clean.
7. Remove the cakes from the oven and allow them to cool in the pans for 10 minutes. Then transfer them to a wire rack to cool completely.

Step 3: Make the Peanut Butter Frosting

8. In a large bowl, beat the softened butter and peanut butter together until creamy and smooth.
9. Gradually add the powdered sugar, one cup at a time, while mixing on low speed.
10. Add the heavy cream, one tablespoon at a time, to achieve your desired frosting consistency—smooth, spreadable, and slightly fluffy.

Step 4: Assemble the Cake

11. Place one cooled cake layer on a serving plate or cake stand. Spread an even layer of peanut butter frosting over the top.
12. Add the second cake layer on top and frost the top and sides of the cake generously. Use an offset spatula for a smooth finish.

Step 5: Prepare the Chocolate Ganache

13. Heat the heavy cream in a small saucepan over medium heat until it begins to simmer. Do not let it boil.
14. Remove the cream from the heat and pour it over the chocolate chips in a heatproof bowl. Let it sit for 2–3 minutes.
15. Stir the mixture until smooth and glossy. Allow it to cool slightly before drizzling.

Step 6: Decorate the Cake

16. Drizzle the ganache over the top of the frosted cake, allowing it to drip down the sides for a beautiful effect.
17. Sprinkle chopped roasted peanuts and/or mini peanut butter cups on top for decoration.
18. Chill the cake for 15–20 minutes to set the ganache before serving.