Wonder why I call this double rainbow cake? Make a guess!
3 egg whites
120g fine sugar
300g Liv cold salted butter, cut into small pieces
2 tsp vanilla essence
1. Place egg whites & sugar in a heatproof bowl. Sit the heatproof bowl on a saucepan filled with water. Bring the water in the saucepan to a slight simmer. Using a balloon whisk, stir the egg whites & sugar constantly until the sugar has fully dissolved.
2. Beat the warm egg white mixture on high speed to obtain stiff peaks using a mixer.
3. Beat in butter into the beaten egg whites in batches until the mixture is firm & fluffy. Add in vanilla essence.