226g unsalted butter, at room temperature
2 1/3cups (426g) granulated sugar
5 large egg whites, at room temperature
2 teaspoons vanilla extract
3 cups (426g) all purpose flour
4 teaspoons baking powder
½ teaspoon salt
1 1/2 cups milk at room temperature
Red, orange, yellow, green, blue and purple gel paste colouring
Preheat your oven to 170 degrees Celsius. Butter and line as many 8-inch round pans( I used 6 inch square pan) that you have. If you have a weighing machine, weigh your mixer bowl and take down the weight of it.
Divide the batter by 6 portion and place in individual bowls. Using a toothpick or metal teaspoon, tint your batter using the gel paste colourings till you get your desired shades. Pour the batter into the lined pans and bake for 18mins each. Once done, let it cool in the pans for about 10mins before removing it and letting it cool completely.