Before you start decorating, you need to prime your cake. Spread a thin layer of frosting to seal in the crumbs—the pros call this a “crumb coat.” Let the icing harden for 30 minutes in the fridge.
1. For the second coat of icing, prepare two different colours by adding drops of food colouring to icing. Mix well until get desired colour.
2. Spread one colour around the bottom half of the cake; spread the other colour around the top half, leaving a bit of space between the two.
3. Using a palette knife or the flat side of a butter knife, smooth the edge of the cake, wiping the knife clean with a paper towel after each swipe.
4. The colours will naturally mix in the middle.
A version of this article appeared in our April 2016 issue with the headline "Piece of cake", p. 51.