Masterclass piñata cake

Pre-heat the oven to 180C/160C Fan/Gas 4. Grease and line 4 x 20cm sandwich tins. Beat together 115g butter and 115g caster sugar until light and creamy. Add a blob of the yellow gel colouring, or a few drops of yellow liquid food colouring, and beat in. Sift 115g of the flour. Beat in 1 egg, then add 1 more egg and a spoonful of the flour. Beat again, then fold in the rest of the 115g flour.

Put the mixture in one of the cake tins and level the top. Now repeat the process to make another layer of cake, colouring the mixture orange by combining yellow and red colouring. Then make a reddish-pink layer using just the red or pink food colouring, and a blue layer with the blue colouring. Bake in the oven for 25 minutes or until the tops spring back when lightly pressed. Remove from the tins and leave to cool completely on a wire rack. Using a spoon, mix the remaining 450g butter with the icing sugar, vanilla and 4 tbsp cold water until the sugar is just blended in, then beat with an electric mixer until light and creamy.

Cut out 10cm rounds from the centres of the orange and pink sponge layers (you can freeze these to eat later). Spread some of the butter icing in a ring on top of the yellow layer, leaving a 10cm circle bare in the centre.

Put the orange sponge ring on top of the iced yellow layer. Spread icing on the orange ring. Put the pink ring on top.

Fill the hole with the sweets. Spread icing on top of the pink ring, then cover with the blue layer. Put 2 heaped tbsp icing in a bowl and thin down with 2tsp water. Spread thinly over the sides of the cake. Divide the rest of the icing into five equal portions. Put two portions together in a bowl and colour yellow. Colour the other portions blue, pink and orange (by mixing yellow and red or pink).

Get four plastic piping bags and cut off the ends. Fill each bag with a different colour icing. Pipe blue icing around the base of the cake, then use a palette knife to spread it around the sides of the first (yellow) layer. Pipe and spread pink icing around the edge of the orange layer, and orange icing around the pink. Pipe and spread some yellow icing around the sides of the top (blue) layer, then spread the rest over the top of the cake. To finish, make a spiral pattern on top using the back of a teaspoon, which has been quickly dipped in boiling water.

Tips:
You'll need four layers of sponge for the cake, so if you only have two cake tins, bake them in two batches. When picking sweets to put in the centre of your cake, look for smaller ones that will tumble out when it's cut and not stick together.