1. Grease and base line 3 x 20cm round baking tins. Preheat the oven to 180oC, gas mark 4. Add all the cake ingredients to the bowl of a stand mixer. Put the mixer on a slow speed to combine the ingredients, then turn it up to a medium/high speed for about a minute.
2. Carefully distribute the mixture equally between the three tins (weigh the tins if you want to be really precise). The batter will be thick, and you should spread it so it covers the tins evenly. Tap the tins on the work surface to knock out any air bubbles.
3. Bake for 25 minutes, until they are golden brown, springy to the touch, and a skewer inserted into the centre comes out clean. Leave the cakes to cool in their tins for 10 minutes, before turning them out onto a wire rack to cool completely.
4. To make the frosting, beat the sifted icing sugar, butter, milk and vanilla extract together in the stand mixer, or using an electric whisk. Turn the mixer speed up to high and keep beating for 5-7 minutes, until light and fluffy.
5. To assemble the cake, put a small amount of frosting in the centre of your cake stand - this will act as a glue and stop the cake moving. Place the bottom layer of the cake on the stand. Spoon some frosting over and spread using a palette knife. Repeat for the remaining layers, then spread frosting over the sides of the cake.
6. To decorate, place candy canes around the sides of the entire cake, pushing them into the frosting and keeping them quite close together. Secure with a festive ribbon. Pile the sweets on top of the cake to finish.