The BEST Chocolate Peanut Butter Buttercream Whoopie Pies! Bake up a dozen of these classic Chocolate Whoopie Pies with this easy homemade recipe. These pies are extra moist with DELICIOUS peanut butter buttercream filling - perfect for desserts and parties!
Preheat oven to 350 degree F. Spray baking sheet or whoopie pie pan.
In a large mixing bowl mix together butter, sugar, baking powder, baking soda, salt and vanilla. Once mixed, add in the egg and continue beating until all smooth. Add in cocoa powder and continue mixing.
Add flour and milk and continue beating until smooth. Make sure it's completely mixed and soft.
Drop the cake dough by 1/4 cupfuls onto baking sheet or fill up whoopie pie pan. If using a baking pan, leave 1 inch between cakes as they will grow.
Bake 11 to 13 minutes until firm. Remove from oven and let cool completely.
Spread peanut butter filling on one pie, while using another pie to press it down.
Enjoy immediately or wrap in plastic wrap to store.
For the peanut butter buttercream
Beat melted butter and peanut butter in a bowl until mixed. Gradually mix in sugar and once thickened, add milk.
Continue beating for about 2 minutes until buttercream is spreadable and fluffy.