This is the cake I make for all of my kids’ birthdays! Delicious, tender cake crumb, speckled with rainbow sprinkles, enveloped in perfectly fluffy homemade buttercream frosting – and then I decorate simply with a rim of more sprinkles to keep the whole thing lovely and loose and festive.
The original, utterly sublime recipe is Samantha Merritt’s of sugarspunrun.com. This one has my tiny tweaks —made mainly out of necessity when I’d run out of certain ingredients — but her original version is perfect and you can check it out HERE! I hope you and your family love it as much as we do… there is nothing like the heavenly smell or caramelizing sugar and vanilla that will perfume your home when this is baking!!
9 tbsp unsalted butter softened
3 cups granulated sugar
1 cup avocado oil
4 tsp vanilla extract
2 cups + 2 tbsp all-purpose flour
2 cups bread flour
4 ½ tsp baking powder
1 ½ tsp salt
1 ½ cup milk
9 egg whites at room temperature
½ cup sprinkles – I try to find ones that are naturally colored, like THESE
1 lb unsalted butter
½ tsp salt
6 cups powdered sugar
6 tbsp heavy cream
2 tsp vanilla extract
•Preheat oven to 350F and prepare 2 8-inch round cake pans by generously greasing with butter. Then cut rounds of parchment paper to fit in the bottom of each. Use to line the bottom of each pan, then flip the paper and rub to line each again so both side of the parchment are greased – this makes for extra easy removal from the pan after cooking.
•Using a standmixer or handmixer fitted with paddle attachments, beat butter on medium-low speed until creamy. Add sugar and avocado oil and beat until all ingredients are well-combined, fluffy and creamy, about 2 minutes. Stir in vanilla extract and beat another 15 seconds to incorporate.
•In a medium bowl, whisk together your dry ingredients: flour, baking powder and salt.
•With mixer on medium speed, alternate adding the dry mixture and the milk to the butter mixture, one third at a time. Stir until each addition is almost completely incorporated before adding the next round.
•In a separate bowl, use a hand mixer with the whisk attachment on high-speed to combine your egg whites. Beat until stiff peaks form, 2-3 minutes. Using a spatula, gently fold your egg whites into your cake mix to preserve as much air and lift as possible. Scrape the sides of the bowl and cut down the middle to evenly distribute.
•Add sprinkles and gently stir until just distributed.
•Evenly divide cake batter into prepared pans. Bake at 350F for 35-40 minutes, or until a toothpick inserted in the center of each cake layer comes out clean. For best results, rotate your cake pans halfway through to ensure even baking. Cakes will be a light golden brown and springy to the touch.
•Remove cakes from oven and allow to cool for 10 minutes before turning out of pans and allowing to cool completely on a cooling rack.
•Meanwhile, make buttercream frosting. With a mixer or handmixer fitted with paddle attachments, whip softened butter on medium speed until creamy. Add salt and beat again for about 20 seconds. Add powdered sugar one cup at a time, thoroughly incorporating each cup before adding the next.
•Add in heavy cream 1 tbsp at a time and whip for 20-30 seconds between each addition. Add vanilla extract and stir on medium-high for 30 seconds.
•Add a dollop of buttercream to the center of your serving plate before placing one layer of your cooled cake on top – this will act like a glue to hold your cake in place. If you want to avoid getting frosting on your serving plate, you can also line the plate with 2 sheets of parchment paper that meet in the middle and can easily be pulled out from under your cake once frosting is complete. Or you can just wipe down the plate when complete. Or you can ignore whatever is there!
•Apply a layer of frosting to the top of the cake. Add the second cake layer, and thinly coat the top of that with more frosting. Then apply a thin coat of frosting to all sides of the cake. Transfer cake to freezer for 10-15 minutes to allow crumb coat frosting layer to set, then remove and apply another clean, thick coat of frosting around the entire cake. Top with sprinkles and eat up!