Surprise M&Ms Cake

Who would ever think that an M&Ms covered cake would be hiding a treasure trove of more M&Ms?


  • Cake Batter:
  • 2 cups all-purpose flour
  • 3 ½ tsp baking powder
  • ½ tsp salt
  • ½ cup unsalted butter, room temperature
  • 1 cup sugar
  • 1 tsp vanilla extract
  • 2 eggs
  • 1 cup milk
  • ¼ cup rainbow sprinkles (NOT the round sprinkles – the colour will bleed into the cake batter! Use the flat, confetti-like sprinkles or the long “jimmies”)
  • Buttercream:
  • 2 cups unsalted butter, room temperature
  • 1 tsp vanilla extract
  • 5 cups confectioner’s sugar
  • 1 cup M&Ms
  • 4 cups M&Ms


  1. Bake the cake: Combine the flour, baking powder and salt in a bowl. In a separate bowl, beat the butter with an electric mixer until pale and fluffy. Add the sugar and mix until combined. Add the vanilla extract and eggs and beat until combined. Add the dry ingredients in 2 additions, alternating with the milk. Then add the sprinkles and mix until just combined. Pour into a greased 9-inch round cake pan and bake at 350F for 20-25 minutes, or until fully cooked. Cool completely.
  2. Make the buttercream: Beat the butter with an electric mixer until pale and fluffy. Add the vanilla extract and beat to combine. Add the confectioner’s sugar one cup at a time, then beat for 3-5 minutes, until fluffy.
  3. Assembly: Remove the crusts of the cake and slice it into 3 layers. Spread some buttercream between each layer, then cut the center out of the middle layer. Fill the middle layer with 1 cup M&Ms. Place the top layer on top, then cover the entire cake in buttercream.
  4. Stick M&Ms onto the cake in the order of the rainbow, pairing each color together in sets of 2. Once you complete one row, shift the second row one M&M to the right, which will create diagonal stripes. Continue until the entire cake is covered in M&Ms.
  5. Slice the cake to reveal the surprise M&M filling! Enjoy!