Ingredients
Equipment
Method
- Preheat your oven to 350 degrees F. This step is crucial for ensuring your cake bakes evenly. While the oven is warming up, prepare your cake pans. Lightly spray 3 9-inch cake pans with baking spray and set them aside. For best results, consider adding parchment paper at the bottom and spray it again with baking spray.
- In a large mixing bowl, combine the all-purpose flour, baking soda, baking powder, and kosher salt. Stir this mixture gently to evenly distribute the ingredients before setting it aside.
- In another large bowl, use a standing mixer to cream together the butter, shortening, and sugar until the mixture is light and fluffy. This process usually takes about 3 to 5 minutes. Make sure to scrape the sides and bottom of the bowl several times. Next, add the eggs one at a time, ensuring each egg is fully incorporated before adding the next. Finally, mix in the vanilla extract until just combined.
- Gradually add one-third of the flour mixture to the wet ingredients, mixing until just combined. Then, pour in the water, buttermilk, and canola oil. Beat the batter until smooth and fully combined.
- Continue adding another third of the flour mixture, mixing well, followed by the milk. Ensure the batter is smooth before you add the last of the flour mixture. This will give your cake a perfectly balanced texture.
- Once everything is mixed, gently fold in the rainbow sprinkles. This will add a fun surprise to each slice of cake!
- Evenly divide the batter among the prepared cake pans. Use a spatula to smooth out the tops if necessary. Bake in the preheated oven for 25 to 30 minutes or until a toothpick inserted in the center comes out clean.
- Once baked, allow the cakes to cool completely in the pans for about 10 to 15 minutes. After that, gently remove them from the pans and place them on a wire rack to cool completely.
- While your cakes cool, prepare the frosting. In a clean mixing bowl, combine the remaining butter and shortening. Beat until smooth. Gradually add the powdered sugar, mixing well. Then, incorporate the remaining vanilla extract and milk. If the frosting is not stiff enough, you can add more powdered sugar, half a cup at a time until you achieve your desired consistency. Lastly, fold in the remaining rainbow sprinkles.
- Once the cakes are completely cool, use a cake leveler or a sharp serrated knife to trim off any domed tops, ensuring an even surface for stacking. Place a cake board on your cake stand, add a few tablespoons of frosting to the center, and set one cake layer on top.
- Spread about 1 cup of frosting evenly over the first layer using a spatula. Carefully place the second layer on top and repeat the frosting process. Finally, place the last cake layer on top, using the remaining frosting to cover the entire cake. You can be generous with the frosting! Pipe dollops of frosting on top for decoration.
- To add a charming touch, garnish the sides of the cake with more rainbow sprinkles and scatter some on top. For the best texture and flavor, place the cake in the fridge for at least 4 to 6 hours before slicing; this allows the frosting to set beautifully.
Notes
When storing leftovers, keep them in an airtight container at room temperature for up to three days or in the fridge for a week. If you want to freeze the cake layers, wrap them tightly and store for up to three months.