01 -
Set your oven to preheat at 350°F (175°C). Coat two 9-inch round pans with butter and a bit of flour.
02 -
In a mixing bowl, combine the flour with the baking powder, baking soda, and salt. Mix well.
03 -
Whip together the peanut butter and softened butter until smooth. Slowly add in the sugar and beat until light and airy.
04 -
Beat in the eggs one at a time, making sure to mix thoroughly between each addition. Stir in the vanilla.
05 -
Carefully add the dry ingredients and buttermilk in batches to the butter mixture. Start and end with the dry ingredients, mixing just until the batter comes together.
06 -
Gently stir the M&M's into the batter with a spoon or spatula.
07 -
Pour the batter evenly into the prepared pans. Bake them for 25 to 30 minutes, or until a toothpick stuck in the center pulls out clean.
08 -
Set the cakes in their pans to cool for about 10 minutes, then move them to a wire rack to cool completely.
09 -
In a large bowl, beat both the butter and peanut butter until smooth. Gradually add the powdered sugar, then mix in the heavy cream and vanilla. Beat until the frosting is fluffy.
10 -
Spread frosting over one of the cake layers. Place the second layer on top and cover the entire cake with frosting.
11 -
Sprinkle a handful of M&M's on top for a colorful finishing touch.