1.Preheat oven to 180°C (160°C fan-forced), line muffin pans with the paper cases.
2.Make cake according to directions on packets. Drop 2½ level tablespoons of the mixture into each paper case, bake about 20 minutes. Stand cakes in pans 5 minutes; turn, top-side up, onto wire rack to cool.
3.To make the butter cream. Beat the butter (and any flavouring if using) in a small bowl with an electric beater until the butter is as white as possible. (This will result in a whiter buttercream which will give you better results if colouring it). Gradually beat in half of the sifted icing sugar, then the milk, then the remaining sifted icing sugar.Beat until the butter cream is smooth and spreadable. Keep scraping down the side of the bowl during beating.
4.Place a quarter of the butter cream into a small bowl, tint white. Divide remaining butter cream between two small bowls, tint one bowl red and the other yellow.
5.Spread red butter cream over tops of 18 cakes in yellow cases, spread yellow butter cream over tops of remaining cakes in red cases.
6.Using picture as a guide, position cakes on board, secure with a little butter cream. Place white butter cream in a piping bag, pipe numbers one to 36 on cakes.
7.Decorate cakes with Killer Python, and snakes, use Curly Wurlys for ladders and Smarties for counters.
Equipment 3 x 12-hole (⅓-cup/80ml) standard muffin pans 36 standard paper cases (18 yellow, 18 red) 45cm-square prepared cake board Decorations 1 Killer Python 3 snakes (2 blue, 1 green) 4 x 25g Curly Wurly bars Smarties Piping takes a little skill, practice on a flat surface before you pipe the numbers on the cakes. You can buy decorating gel for piping, but we found that the butter cream was easier to use. You’ll have about 1 cup of the cake mixture left over, enough for about four more cakes.