Adapted from Christina Tosi’s Birthday Cake
Makes 2 cakes (with 4 waffle layers)
115g butter, at room temperature
200g castor sugar
50g light brown sugar
3 Free-range eggs
110g buttermilk (1/2 cup)
65g oil (1/3 cup) *see note
2 teaspoons vanilla extract
245g cake flour (2 cups)
1 1/2 teaspoons baking powder
3/4 teaspoon salt
50g rainbow sprinkles (1/4 cup)
plus extra for topping
Non-stick spray, as needed
Combine the butter and sugars in the bowl of a standing mixer fitted with the paddle attachment and cream together on medium-high for 2 to 3 minutes. Add the eggs one at a time, scraping down the sides of the bowl between additions.
On low speed, stream in the buttermilk, oil, and vanilla. Increase the mixer speed to medium-high and paddle for 4 to 6 minutes, until the mixture is practically white, twice the size of your original fluffy butter-and-sugar mixture, and completely mixed. Don’t rush the process - you’re basically forcing too much liquid into an already fatty mixture that doesn’t want to make room for that liquid. There should be no streaks of fat or liquid. Stop the mixer and scrape down the sides of the bowl.
On very low speed, add the cake flour, baking powder, salt, and the 50 g (¼ cup) rainbow sprinkles. Mix briefly, just until your batter comes together. Scrape down the sides of the bowl.
Using a spatula, spread the cake batter into the waffle iron - careful not to overfill.
Cook until the outside of the waffle looks golden and the cake mixture is cooked. The amount of cooking time depends on the thickness of the waffle iron grid. It should take roughly 4-6 minutes.
Remove the cooked waffles and place on a wire rack - stacking the waffles on top of each other and even covering with a clean dish towel. Repeat with the remaining cake mixture.
*Note: Use any oil that has a mild-flavour or no flavour. I used sunflower oil.
makes about 2 cups
200g unsalted butter, at room temperature
135g cream cheese
200g icing sugar
1/2 lemon, juice
Combine the butter and cream cheese in the bowl of a stand mixer fitted with the paddle attachment and cream together on medium-high for 2 to 3 minutes, until the mixture is smooth, fluffy and pale. Scrape down the sides of the bowl.
Add the vanilla and icing sugar and mix on low speed just to incorporate them into the batter. Crank the speed back up to medium-high and beat for 2 to 3 minutes, until you have a white and smooth frosting. Lastly add the lemon juice and mix until incorporated.
Crumb cake Topping
makes about 2 cups
125g light brown sugar
90g cake flour (3/4 cup)
2g baking powder (1/2 teaspoon)
1/2 teaspoon salt
2 tablespoons rainbow sprinkles
40g unsalted butter, melted
1 teaspoon vanilla extract
Heat the oven to 180’c.
Combine the sugar, flour, baking powder, salt, and sprinkles in the bowl and mix to combine.
Add the butter and vanilla and rub in with your fingertips until it resembles coarse sea sand. It doesn't have to be perfectly rubbed in, it great if there are some smaller and bigger clusters.
Bake for roughly 10 minutes until just starting to turn a light golden colour.
Allow to cool before using.
To assemble the cake
Spread an even layer of frosting onto one cake waffle and repeat until all the cake waffles are finished. Finish with a generous layer of frosting on the top layer, sprinkle with crumb cake topping and extra rainbow sprinkles.