2 cups sugar
2 1/2 cups flour
1 cup milk
3/4 cup vegetable oil
2-1/4 tsp. baking powder
1 tsp. vanilla
Best Ever Buttercream (see blog entry)
M&M’s split into individual colours
Preheat oven to 180 °.
Beat sugar and eggs together until slightly thickened. Add flour, milk, oil, baking powder, and vanilla and beat until the batter is smooth and creamy (Don't overbeat).
Divide batter into bowls and mix in colouring.
Pour each bowl into baking tin, carefully dropping each into the centre of the tin - they will spread outwards to fill the tin.
Bake for 30 to 40 minutes.
Cut a circle out of the centre of the cake and then in half to form the rainbow shapes. Using a spatula, spread buttercream over the cakes, covering completely.
Arrange m&ms over the top of rainbows.