Cake decorating has always been super challenging for me, thus, mastering the art has become my most recent endeavor. Decorating this funfetti cake took me a lot of time (like 4 hours) and a ton of focus, but it was worth it. I love the way the cake looks and the flavor speaks for itself (thanks Martha).
I followed Martha Stewart’s recipe exactly, since she is the queen.
2 1/2 cups cake flour
3/4 cup all purpose flour
1 tbsp baking powder
1tsp baking soda
1/2 cup butter
1/2 cup vegetable shortening
1 3/4 cup sugar
2 tbsp vanilla extract
1 cup cold water
1/2 cup whole milk
1/2 cup buttermilk
1 cup sprinkles (rainbow jammies – the long ones, not the circle ones in the picture below, work best)
3 egg whites
1/4 tsp cream of tarter
7 egg whites
1 1/3 cup sugar
1/2 vanilla bean, halved lengthwise
Preheat the oven to 325ºF and butter 3, 8-inch round cake pans.
Mix 2 1/2 cups cake flour, 3/4 cup all-purpose flour, 1 tbsp baking powder, and 1 tsp baking soda in a medium bowl and set aside. In the bowl of an electric mixer with the paddle attachment, beat 1/2 a cup of butter with 1/2 a cup of shortening. Cream for 3 minutes. Add 1 3/4 cup sugar and 2 tbsp vanilla extract. Cream for 1 minute. Add the egg and beat until combined.
In a small bowl, mix 1 cup of cold water with 1/2 cup of whole milk and 1/2 cup of buttermilk. (I didn’t have buttermilk on hand, so I made by own by mixing 1/2 cup whole milk with 1 tbsp lemon juice. Wait 5 minutes for the milk to curdle and you have your very own buttermilk!) With the mixer on low, add the milk mixture and flour mixture to the batter – beginning and ending with the flour mixture. Using a spatula, gently fold in the rainbow sprinkles. Be sure to use rainbow jammies (not the ones in my photo above, as those will melt into the batter and you won’t have sprinkle cake.)
In a separate bowl, whisk 3 egg whites with 1/4 tsp cream of tarter until the egg whites form soft peaks – about 10 minutes. Gently fold the egg whites into batter. Pour the batter evenly into the three cake pans and bake for 40-45 minutes. Check the doneness of the cakes by inserting a toothpick into the center of the cake, if it comes out clean your cake is ready!
Let the cakes cool in the pans for an hour, then transfer them to a wire wrack and let them cool for 2 more hours. When the cakes have reached room temperature, wrap them in saran wrap and freeze overnight.
Place 1 1/3 cup of sugar in the food processor. Scrape in the vanilla beans. Mix well and place the sugar mixture in a heat proof bowl. Add 7 egg whites to the sugar and place the bowl over a pot of simmering water. Whisk the mixture until the sugar is dissolved and the mixture reads 160ºF. Remove from the heat and whisk the mixture until it becomes glossy and peaks form.
Frosting - How to
Remove the cakes from the freezer. Place 3 squares of parchment paper onto your cake stand. Place your first cake layer on your stand and frost the top. Repeat this for the other 2 cake layers. On the third layer add lots of frosting, allowing the frosting to fall down onto the sides of the cake. Using an offset spatula, spread the frosting as much as you can onto the sides of the cake. If there are large gaps in between each layer of cake, pipe the frosting into the gaps. Then finish frosting the sides of the cake.
Using 1/4 measuring cup or your hand, pour the sprinkles onto the top of the cake. Be very generous here! Using the help of a friend, tilt the cake stand a tiny bit onto its side, and pour the sprinkles onto the side of the cake. Be very careful not to tilt the stand too much…or you will end up no cake at all. This process creates a rainstorm of sprinkles, so have your vacuum cleaner handy! Rotate the cake until there are no bald spots. It’s hard to get it exactly, but try your best. Remove the parchment paper from underneath the cake – it should slide out easily.