Rainbow Cake

Butter Cake

1. Preheat oven to 180°C.
2. Line the base of an 8-inch (20cm) round spring form pan with baking paper. Butter the base and edge of pan.
3. Mix flour, baking powder, sugar and salt in a large bowl.
4. With the mixer on high speed, beat together butter, sugar and vanilla until pale and creamy.
5. Switch mixer to medium speed and add eggs one at a time, beating until just combined.
6. Switch mixer to low speed and gradually beat in the dry ingredients, alternating with milk.
7. Divide the batter evenly into seven bowls and add food colouring to each batter until desired colour is reached. Each layer will need to be baked separately.
8. Spread one of the coloured batters into the prepared pan and bake for 10-13 minutes. Cake is ready when a skewer inserted into the centre comes out clean.
9. Cool in pan for 5 minutes. Remove from pan onto a wire rack to cool.
10. Rinse cake pan with cold water until cool. Reline base of tin with baking paper and repeat baking process for the remaining six layers. Tip: always bake with a cool pan.

Cream Cheese Icing

1. Beat cream cheese, butter and vanilla in a large bowl on medium speed until creamy.
2. Gradually add icing sugar.

To assemble

1. Use a spatula to spread a thin layer of icing between each coloured layer.
2. Spread the remaining icing across the top and around the sides.
3. Decorate with coloured rocks.