Funfetti Cake Recipe

Preheat the oven to 350F/177C convection (325F/163C conventional) and grease and line three 6 inch cake pans.
In a medium bowl, whisk together the flour, baking powder and salt until they're evenly distributed.
2 1/4 (270g) cups all-purpose flour spooned & leveled, 1 Tbsp (10g) baking powder, 1/2 tsp salt
In the bowl of an electric mixer fitted with the whisk attachment, beat the butter and the granulated sugar for 2 minutes. Add the oil and continue beating for a minute.
1/4 cup (60g) unsalted butter room temperature, 1 1/2 cup (300g) granulated sugar, 1/2 cup (120mL) vegetable oil
Add the eggs, one at a time, beating on medium speed until each egg is fully incorporated. Add the sour cream and vanilla extract and beat just until combined.
3 large eggs room temperature, 3/4 cup (170g) sour cream room temperature, 2 tsp artificial vanilla extract*, 1 tsp pure vanilla extract*
Add half of the dry ingredients to the wet ingredients, turn the mixer on low speed and then pour in the milk, followed by the rest of the dry ingredients. Fold in the sprinkles, just until they're evenly dispersed.
3/4 cup (180mL) milk room temperature, 1/2 cup (75g) rainbow sprinkles
Distribute the batter evenly among the three cake pans, about 15oz in each pan and bake for 30-35 minutes. When the cake is fully baked it will release itself from the edge of the pan and it will spring back if you press on the center of it.
Allow the cakes to cool completely before frosting.

Place the butter in the bowl of an electric mixer and use the whisk attachment to beat the butter on medium-high speed for 1-2 minutes, until the color turns to a pale yellow, scraping the edge of the bowl half way through.
1 cup (227g) unsalted butter room temperature**
Add the salt and the powdered sugar to the butter and mix on low speed, just until combined. Turn the mixer to medium-high speed and beat the buttercream for at least five minutes, until all of the sugar is fully dissolved and the buttercream no longer feels gritty.
1/8 tsp salt, 4 cups (480g) powdered sugar spooned & leveled
With the mixer on low speed, slowly pour in the heavy whipping cream, vanilla bean paste and vanilla extract and beat for another 2 minutes on medium-high speed. If the buttercream is too soft to frost, refrigerate it for just a few minutes.
3-4 Tbsp (45-60mL) heavy whipping cream room temperature, 1 tsp (8g) vanilla bean paste, 1 tsp artificial vanilla extract

To frost the cake, place the first layer of cake on a flat surface and use 1/4 of the buttercream to frost the first layer. Repeat with the second layer and then place the third layer of cake on top.
Smooth any buttercream that squished out on the edges of the cake and then refrigerate the cake for 15 minutes, or until the cake feels firm enough to frost (make sure it's not wobbly)
For the crumb coat, place 1/4 of the buttercream on top of the cake and use an offset spatula to smooth it out and spread it evenly throughout. It doesn't have to be perfect. Refrigerate the cake for at least another 15-30 minutes, or until the frosting feels set.
Place the rest of the buttercream on top of the cake, use an offset spatula to spread the frosting around and then use a turn table and a cake scraper to create a smooth finish on the cake.

Use an offset spatula to create swirls on top of the cake and then top with sprinkles.
sprinkles
For the paint splatters, place a drop of gel food coloring along with 1-2 drops of vanilla extract in a small bowl. Use a small paint brush to mix it and then use your finger to splash the bristles onto the cake. Repeat with desired colors.
gel food coloring, vanilla extract