Perfect Birthday Funfetti Cake

Makes: 20 Squares Prep Time: 15 Minutes, Cooking Time: 30 MINUTES


It might seem weird to add boiling water to icing but trust me, it makes for the smoothest, fluffiest icing imaginable. Once you try this method you won’t come back.


  • 400g unsalted butter, softened
  • 350g caster (superfine) sugar
  • 6 large eggs
  • 2 tsp vanilla bean paste
  • 430g plain (all-purpose) flour
  • 1 tsp baking powder
  • 300ml buttermilk or natural yoghurt
  • 80g large sugar sprinkles (about 10 tbsp)
  • For the icing:
  • 200g unsalted butter, softened
  • 300g icing (confectioner’s) sugar
  • 2 tsp vanilla bean paste
  • Pink food colouring
  • 1-2 tbsp just-boiled water
  • Sprinkles, to decorate
  • Utensils:
  • KitchenAid mixer
  • Baking Tray
  • Skewer
  • Large bowl for icing
  • Spatula
  • Handmixer
Preheat the oven to 200°C/180°C fan/400F/Gas 6 and grease and line a 33 x 23cm (13 x 9in) baking tray or cake tin.
Cream the butter and sugar together until light and fluffy. Gradually add the eggs and vanilla bean paste, mixing well between each addition.
Gently fold in one-third of the flour, the baking powder and one-third of the buttermilk or yoghurt; repeat until you have added all of the flour and buttermilk.
Bake for 50 minutes until risen and lightly golden and a skewer inserted in the centre comes out clean (this step is very important as ovens can vary). Cool in the tin for 5-10 minutes, then turn out onto a wire rack to cool completely.
Meanwhile, make the icing. Beat the butter until light and fluffy then gradually beat in the icing sugar until you have a smooth icing. Add the vanilla bean paste, food colouring and 1-2 tablespoons of just-boiled water. Whisk together to make a bright, smooth icing.
Once the cake is cool, transfer to a serving plate or board. Spread the icing all over the cake with a swirly pattern then scatter with the sprinkles and serve.