Preheat oven to 180°C. Line a muffin pan with cupcake cases.

In a bowl, mix together the flour, baking powder and salt. In other bowl, whisk together the milk, buttermilk and vanilla essence. In another bowl, combine the butter and sugar, beat medium with electric hand mixer, 2-3 minutes. Scrape down sides. Reduce to speed, add the 2 whole eggs and beat until incorporated. Add the egg whites and beat again until incorporated.

Addd the flour mixture, alternating with the milk mixture, mix to a smooth batter. Fill cup cases 3/4 full with batter and bake for 20-25 minutes. Allow to cool before frosting.

Vanilla Buttercream:
Beat the butter and icing sugar until fluffy. Add milk, vanilla essence and salt. Add food colouring of your choice and beat further for about 2 minutes until all the colour is incorporated and butter cream is light and fluffy.

Use piping and nozzle to decorate the top of the cupcakes with butter cream.