This bright-as-a-button cake will bring a smile to anyone's face.


  • 375g unsalted butter, softened
  • 3 teaspoons vanilla extract
  • 2 1/2 cups caster sugar
  • 4 eggs
  • 4 1/2 cups self-raising flour
  • 1 1/2 cups milk
  • Violet, sky blue, leaf green, pink and lemon yellow gel food colourings
  • 1 1/2 tablespoons banana-flavoured Nesquik powder (optional, see note)
  • 2 teaspoons strawberry essence (optional, see note)
  • 7 red, 18 orange, 24 yellow, 28 green and 36 blue M&Ms, to decorate
  • 12 pink and 40 purple Smarties, to decorate
  • 500g unsalted butter, softened
  • 6 cups icing sugar mixture
  • 2 teaspoons vanilla extract
  • White icing colouring (optional)


  1. Preheat oven to 180C/160C fan-forced. Grease two 7cm-deep, 20cm-round cake pans. Line base and sides with 2 layers of baking paper.
  2. Using an electric mixer, beat butter, vanilla and sugar until light and fluffy. Add eggs, 1 at a time, beating until combined after each addition. Add flour. Beat on low speed, gradually adding milk, until just combined. Divide mixture between 5 bowls. Using food colouring, tint 1 portion purple and remaining portions blue, green, pink and yellow. Add banana-flavoured powder to yellow mixture and strawberry essence to pink mixture, stirring to combine.
  3. Using half of each coloured mixture, drop tablespoons of the mixtures, alternating colours, into 1 prepared cake pan. Repeat with remaining mixtures and cake pan. Run a butter knife back and forth through both mixtures to create a slight marbled effect (don