01 -
Set the oven to 350°F (175°C). Coat two 9-inch round pans with grease and sprinkle with flour.
02 -
In a mixing bowl, combine 1 1/2 cups flour, 1 tsp baking powder, 1/2 tsp baking soda, and 1/4 tsp salt using a whisk.
03 -
Beat 1/2 cup butter and 1/2 cup peanut butter together in a large bowl until it’s smooth and light.
04 -
Slowly mix in 1 cup sugar, beating until fluffy. Add eggs one after the other, mixing well each time. Stir in 1 tsp vanilla extract.
05 -
Mix the dry ingredients and 1/2 cup buttermilk into the peanut butter blend a little at a time, starting and ending with the dry ingredients. Combine gently.
06 -
Carefully fold in 1 cup of M&M's.
07 -
Pour the mix equally into the prepared pans. Bake for 25-30 minutes or until a toothpick pulled from the middle comes out without batter.
08 -
Leave the cakes to rest in the pans for 10 minutes, then move them to a cooling rack to cool fully.
09 -
For the frosting, mix 1/2 cup butter and 1 cup peanut butter in a large bowl until smooth and creamy.
10 -
Add 2 cups powdered sugar gradually, mixing until smooth. Finish by beating in 1/4 cup heavy cream and 1 tsp vanilla until fluffy.
11 -
Spread frosting over one cake layer. Place the second layer over it and cover the top and sides with more frosting.
12 -
Sprinkle extra M&M's on the frosted cake to finish it off.