How to make:

1. Rainbow Cake: Beat eggs, sugar, and emulsifier until thick and pale.
   Add the sifted mixture of MELATI flour, cornstarch, and milk powder. Mix well.
   Pour in melted margarine, stir gently with a spatula until evenly mixed.

2. Divide the batter into 7 portions.
   Add different food coloring to each portion and mix well.
   Pour into a 15 × 15 × 4 cm baking pan lined with parchment paper.

3. Bake in a preheated oven at 200°C (392°F) for about 25 minutes or until cooked.
   Let cool, then cut into cubes.

4. For the Cake: Prepare three 20 cm round cake pans, grease with margarine, and line with parchment paper. Set aside.

5. Beat eggs, sugar, emulsifier, and rum essence until thick and pale.
   Add the sifted mixture of MELATI flour, cornstarch, and milk powder. Mix well.
   Add melted margarine, stir gently until well combined. Divide the batter into three portions.

6. Pour a little batter into each prepared pan, then arrange the colorful rainbow cake cubes on top in a random pattern.
   Pour the remaining batter over the cubes.

7. Bake at 200°C (392°F) for about 25 minutes or until cooked. Let cool.

8. Spread whipped cream over each cake layer, stack them, and coat the entire cake with buttercream.
   Decorate with sprinkles on top.

Yields1 whole cake.