Beat butter and sugar using an electric whisk until its creamy.
Add eggs one by one and keep whisking, at this stage you might feel that your batter is getting too wet but keep whisking till it achieves creamy texture.
Add vanilla essence.
Sieve in flour and baking powder into the wet mixture and mix using cut and fold method.
Preheat oven at 180 degree Celsius.
Divide batter into six equal portions, add food colors.
Grease 6 inch cake tins, transfer the batter, give it a tap on the floor and place it in the oven for 20-25 minutes.
Check with skewer if the cakes are cooked from inside. Once they are out of oven, let them cool down for an hour or you can make your sponges one day prior.