These little beauties take us back to childhood parties - the sprinkles make an appearance not only on the outside of the cake, but also in the batter itself. We were inspired by Momofuku Milkbar's famed birthday layer cake for the cake recipe, but ours is frosted with a fluffy buttercream. Candles optional.
- 100 gm softened butter
- 110 gm caster sugar (1/2 cup)
- 55 gm brown sugar (1/4 cup)
- 3 eggs
- 125 ml well-shaken buttermilk (1/2 cup)
- 80 ml vegetable oil (1/3 cup)
- 1 tsp vanilla bean extract
- 300 gm plain flour (2 cups)
- 1½ tsp baking powder
- 1/4 cup rainbow sprinkles, plus extra to serve
- 4 eggwhites
- 200 gm caster sugar
- 200 gm softened butter
- 1Preheat oven to 170C, and butter and flour four 10cm-diameter cake tins. Beat butter, sugars and ½ tsp sea salt in an electric mixer until light and fluffy (4-5 minutes), then scrape down sides of bowl and add eggs one at a time, beating well between additions. Scrape down sides and base of bowl and beat until mixture is very pale and almost doubled in volume (4-5 minutes).
- 2Combine buttermilk, vegetable oil and vanilla, and, while beating, gradually add to mixer, pouring down the side of the bowl. Sieve in flour and baking powder, add sprinkles and fold to combine, then divide among prepared cake tins, filling to 1.5cm below rims and smoothing tops (you'll have a little mixture leftover). Bake until golden brown and centres spring back when lightly pressed (20-25 minutes). Cool in tin for 5 minutes, then turn out onto a wire rack to cool completely.
- 3For meringue buttercream, combine eggwhites, sugar and a pinch of salt in the bowl of an electric mixer placed over a saucepan of simmering water and whisk until warm to the touch and sugar dissolves (4-5 minutes; mixture should feel smooth and not grainy when you rub it between your fingertips). Return the bowl to the mixer and whisk mixture until cooled to room temperature and firm peaks form (18-20 minutes; check the bottom of the bowl to make sure it's completely cool), then gradually add butter a few tablespoons at a time, whisking well between additions. When all the butter is incorporated, beat with a paddle attachment on low speed to remove air bubbles.
- 4Spread buttercream over sides and tops of cakes with a hot, wet palette knife, then scatter sides with extra sprinkles, gently pressing them on, and serve.