Step 1: Prepare the Cake - If you're using a box cake mix, follow the instructions on the package to prepare the batter. If you're making the Perfect Chocolate Cake, combine the dry ingredients in a bowl, then mix in the wet ingredients according to your recipe.
Step 2: Bake - Preheat your oven to 350°F (175°C). Grease and flour your 9-inch round cake pans. Pour the batter evenly into the prepared pans and bake for about 25-30 minutes, or until a toothpick inserted in the center comes out clean. Once baked, let the cakes cool in the pans for 10 minutes before transferring them to a cooling rack.
Step 3: Make the Peanut Butter Frosting - In a large mixing bowl, cream together the softened butter and smooth peanut butter using an electric mixer. Add in the vanilla extract and mix until combined. Gradually add the powdered sugar, one cup at a time, mixing well after each addition. If the frosting is too thick, add a tablespoon of milk to reach your desired consistency. Finish with a pinch of salt to enhance the flavors.
Step 4: Assemble the Cake - Once the chocolate cake layers have completely cooled, place one layer on a serving plate. Spread a generous amount of peanut butter frosting on top. Add the second layer and frost the top and sides of the entire cake.
Step 5: Decorate - To elevate your Reeses Cake, top it with regular size and mini peanut butter cups. Drizzle chocolate sauce over the top for an extra touch of indulgence, if you desire.