Rainbow Cake

• 675 g (1.49 lb / 5½ sticks) unsalted butter, plus extra for greasing
• 675 g (1.49 lb / 3 cups) superfine sugar
• 1 tbsp vanilla extract
• 12 medium or 10 large (about 500 g) eggs
• 675 g (1.49 lb / 5 cups) self-raising flour
• 1 tbsp baking powder
• ½ tsp each of red, orange, yellow, green, blue, purple food colourings
• 500 g (1.1 lb / 4 sticks) unsalted butter
• 1 kg (2.2 lb / 8 cups) powdered sugar
• 3 tbsp milk
• 1 tbsp vanilla extract
• Sprinkles (eg. hundreds and thousands) (optional)

Ingredients for 48 servings (4.1 kg) · the original recipeShow how each ingredient was counted

Method

1. 1

   Make cake: Preheat the oven to 190 C. Grease and line six 20 cm round cake tins.

   Oven
2. 2

   Beat the butter, sugar and vanilla in a large mixing bowl, until soft and fluffy.

3. 3

   Beat in the eggs, two at a time.

4. 4

   Combine the flour and baking powder. Fold this dry mixture into the batter.

5. 5

   Divide the mixture into 6 separate bowls.

6. 6

   Add the red food colouring, one drop at a time, to the mixture in one bowl and stir in until the mixture reached the desired colour.

7. 7

   Repeat step 6, using orange, yellow, green, blue and purple food colourings.

8. 8

   Spread the red mixture in one of cake tin. Repeat with other colours.

9. 9

   Bake for 25 minutes, in batches of two cakes, until a skewer inserted comes out clean.

   Oven
10. 10

    Transfer the cakes to a wire rack and leave to cool. Unmold cakes.

11. 11

    Make icing: For the icing, beat the butter in a mixing bowl until soft.

12. 12

    Add half of the icing sugar, 1 cup at a time, and beat in.

13. 13

    Beat in the milk and vanilla extract.

14. 14

    Add the rest of icing sugar, 1 cup at a time, and beat in.

15. 15

    Assemble cake: Spread one-eighth of the icing onto the purple cake. Top with blue cake layer, and press gently.

16. 16

    Repeat the frosting and cake layering in rainbow order, finishing with the red layer.

17. 17

    Spread the rest of icing all over the cake.

18. 18

    If you like, sprinkle the cake with sprinkles.

19. 19

    Enjoy!