Funfetti Recipe

Prepare and preheat

Preheat the oven to 350°F (175°C). Grease and flour two 8-inch round cake pans (or three 6-inch pans) and line the bottoms with parchment circles. Set aside to cool after baking.

Combine dry ingredients

In a medium bowl whisk together the all-purpose flour, baking powder, and fine salt until evenly combined. Set aside.

Cream butter and sugar with oil

In the bowl of a stand mixer fitted with the paddle (or in a large bowl with a hand mixer), cream the softened butter and granulated sugar on medium speed until light and fluffy, about 3–4 minutes. With the mixer running, stream in the vegetable oil and beat for 30 seconds to incorporate.

Add eggs and vanilla

Add the eggs one at a time, beating well after each addition and scraping the bowl as needed. Add the vanilla extract and mix until combined.

Alternate dry and wet

With the mixer on low, add one-third of the flour mixture, then half of the milk, then another third of the flour, then the sour cream, and finish with the last third of the flour and the remaining milk. Mix just until combined after each addition — do not overmix. Scrape the bowl to ensure no pockets of flour remain.

Fold in sprinkles

Using a rubber spatula, gently fold in the rainbow sprinkles until evenly distributed. Be gentle and fold only until incorporated to avoid bleeding colors and deflating the batter.

Bake

Divide the batter evenly between the prepared pans (use a kitchen scale or measuring cups). Smooth the tops. Bake at 350°F (175°C) for 22–28 minutes for 8-inch pans (or 18–22 minutes for 6-inch pans), or until a toothpick inserted in the center comes out clean or with a few moist crumbs. Rotate pans halfway through baking for even color.

Cool

Allow the cakes to cool in the pans on a wire rack for 10–15 minutes. Run a thin knife around the edges, invert onto the rack, remove parchment, then cool completely before frosting (at least 1 hour).

Beat butter

Place the softened butter in a large bowl or stand mixer and beat on medium speed until smooth and pale, about 2–3 minutes.

Add sugar gradually

Reduce mixer speed to low. Gradually add the sifted confectioners' sugar, one cup at a time, mixing until incorporated and scraping the bowl between additions to prevent lumps and dust clouds.

Add flavor and adjust texture

Once all the sugar is added, increase speed to medium and add the vanilla extract, fine salt, and heavy cream (or milk) one tablespoon at a time. Beat for 2–3 minutes until the buttercream is light, smooth, and spreadable. If too stiff, add an additional teaspoon of cream; if too loose, add 1/4 cup more powdered sugar.

Tint (optional)

If using gel colors for piping accents, divide a small portion of buttercream into separate bowls and tint with gel food coloring to desired shades. Use sparingly — a little gel color goes a long way.

Level and stack

If cake layers have domed, level them with a serrated knife or cake leveler. Place the first layer on your serving plate or cake board. Pipe or spread an even layer (about 3/4 to 1 cup) of buttercream on top. Repeat with remaining layers, stacking carefully so the edges align.

Crumb coat

Apply a thin crumb coat of buttercream to the entire cake — a light layer to trap crumbs. Chill the cake in the refrigerator for 20–30 minutes to firm the crumb coat.

Final coat and smooth

Apply a final generous layer of buttercream and smooth with an offset spatula or bench scraper. For a smoother finish, dip the spatula in hot water, dry it, and lightly glide to remove ridges.

Add sprinkles

While the frosting is still slightly soft, press extra rainbow sprinkles around the base and on the sides, or gently toss them on the top edge to create a confetti rim. For a neat band, hold the cake over a tray and press sprinkles against the frosting with your fingers or a small offset spatula.

Pipe accents (optional)

If you tinted small batches of buttercream, fit piping bags with desired tips and pipe rosettes, stars, or dots on the top or along the base. Use contrasting sprinkle colors and sizes for visual interest.

Chill and serve

Chill the decorated cake for 15–30 minutes to set the frosting for cleaner slices. Bring to room temperature 20–30 minutes before serving for best flavor and texture.