Vanilla Sprinkle Recipe

Preheat and prepare pans

Preheat the oven to 350°F (175°C). Grease and line the bottom of two 8-inch round cake pans with parchment paper and lightly flour the sides, or use nonstick spray.

Whisk together the dry ingredients: in a medium bowl, combine 2 cups all-purpose flour, 1 cup granulated sugar, 2 tsp baking powder, and 1/2 tsp fine salt. Whisk until evenly distributed.

Combine wet ingredients: in a large bowl or stand mixer bowl, whisk together 1/2 cup melted cooled unsalted butter, 3/4 cup whole milk, 1/4 cup sour cream, 2 large eggs, and 2 tsp pure vanilla extract until smooth.

Combine wet and dry: add the dry ingredients to the wet mixture in two additions, folding or mixing on low speed after each addition just until incorporated. Scrape the bowl and avoid overmixing; batter should be smooth and slightly thick.

Stir in sprinkles: gently fold 1/2 cup rainbow sprinkles into the batter using a spatula. Toss the sprinkles in a tablespoon of flour beforehand if you want to reduce sinking; fold gently to avoid color bleed.

Divide and bake: divide the batter evenly between the prepared pans, smoothing the tops. Bake in the center of the preheated oven for 22–28 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.

Cool: let the cakes cool in the pans for 10 minutes, then invert onto a wire rack, remove parchment, and cool completely (about 1 hour) before frosting.

Beat the butter: using a stand mixer fitted with the paddle attachment or a hand mixer, beat 1 cup room-temperature unsalted butter on medium-high speed for 2–3 minutes until creamy and pale.

Add sugar and salt: reduce speed to low and gradually add 3 cups sifted confectioners' sugar, about 1 cup at a time, mixing until incorporated. Add 1/4 tsp fine salt as you go.

Add vanilla and cream: scrape the bowl, then add 1.5 tsp pure vanilla extract and 2 tablespoons heavy cream. Beat on medium-high for 2–3 minutes until light and fluffy. If buttercream is too thick, add an extra teaspoon of cream; if too thin, add a little more powdered sugar until desired piping consistency.

Adjust and finish: taste and adjust salt or vanilla as needed. Fold in a light 1–2 tablespoon sprinkle of rainbow sprinkles into a small portion of buttercream if you want a confetti interior, or reserve all sprinkles for outer decoration.

Level and fill: if the cake layers are domed, level the tops with a serrated knife. Place one layer on a cake board or serving plate. Spread about 3/4–1 cup of buttercream evenly over the first layer.

Stack and crumb coat: place the second layer on top and apply a thin crumb coat (a light layer of frosting) over the entire cake to seal crumbs. Chill the cake in the refrigerator for 15–20 minutes to set the crumb coat.

Final frosting: apply the remaining buttercream in an even layer using an offset spatula. Smooth the sides and top as desired.

Decorate with sprinkles: press 1/4 cup rainbow sprinkles around the sides of the cake and scatter the remaining sprinkles on top. If you reserved a small portion of buttercream with sprinkles mixed in, pipe a few rosettes on the top and finish with a pinch of sprinkles.

Optional garnish: scrape a little of the seeds from 1 vanilla bean or dot a small amount of vanilla paste on top for added aroma and visual appeal.

Chill and serve: refrigerate the cake for 10–15 minutes to set the frosting if needed. Bring to room temperature before serving for best flavor and texture. Slice with a sharp knife wiped between cuts.