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Copycat Costco Vanilla Cake Recipe

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★★★★★

5 from 91 reviews

This Copycat Costco Vanilla Cake recipe replicates the beloved bakery-style vanilla layer cake featuring moist, fluffy cake layers and a creamy, smooth buttercream frosting. The cake is filled with a copycat vanilla mousse and adorned with sprinkles for a festive touch. It’s perfect for celebrations and special occasions, offering that perfect balance of classic vanilla sweetness and rich texture.

Ingredients

Scale

For the Cake:

  • 2 1/2 cups plus 2 tablespoons cake flour
  • 1 1/2 cups plus 2 tablespoons granulated sugar
  • 1 tablespoon baking powder
  • 3/4 teaspoon fine salt
  • 3/4 cup unsalted butter, very soft
  • 4 large egg whites, room temperature
  • 1 large egg yolk, room temperature
  • 1 tablespoon vanilla extract
  • 1 cup buttermilk, room temperature

For the Buttercream:

  • 2 tablespoons water
  • 2 tablespoons cornstarch
  • 1 cup unsalted butter, very soft
  • 1/2 cup vegetable shortening, room temperature
  • 4 cups powdered sugar
  • 1/2 teaspoon fine salt
  • 1 tablespoon vanilla extract
  • 3 to 4 tablespoons whole milk or heavy cream, room temperature

For Assembling the Cake:

  • Copycat Costco Vanilla Mousse (prepared separately)
  • Sprinkles for garnish

Instructions

  1. Prepare the Cake Pans: Preheat your oven to 350°F. Spray two 8-inch cake pans with baking spray and line the bottoms with parchment paper. Set aside to prepare the batter.
  2. Combine Dry Ingredients: In a large mixing bowl, sift together the cake flour, granulated sugar, baking powder, and fine salt to evenly distribute all dry ingredients.
  3. Mix in Butter: On low speed, gradually add the very soft unsalted butter to the dry mixture. Beat until the mixture resembles coarse sand or looks softer depending on your climate. Continue beating for 1 to 2 minutes, scraping sides and bottom as needed.
  4. Add Egg Whites and Egg Yolk: Add the four egg whites one at a time, beating well after each addition to incorporate air for fluffiness. Then beat in the single egg yolk and vanilla extract until combined.
  5. Add Buttermilk: With mixer on low, slowly add buttermilk in three additions. Beat for 1 to 2 minutes after each addition to create a smooth, evenly blended batter.
  6. Bake the Cakes: Divide the batter evenly between the prepared pans. Bake for 26 to 30 minutes, or until cakes are golden on top and a toothpick inserted into the center comes out with a few moist crumbs but no raw batter.
  7. Cool the Cake Layers: Let the pans cool for 5 minutes on a wire rack, then invert to remove cakes and peel off the parchment paper. Allow cakes to cool completely before assembling. Wrap and refrigerate if assembling the next day.
  8. Prepare the Buttercream: Whisk water and cornstarch in a small bowl to combine and set aside. In a large bowl, beat the butter and vegetable shortening on medium speed until light and fluffy, about 3 to 4 minutes.
  9. Add Cornstarch Mixture and Powdered Sugar: Mix in the cornstarch-water mixture. On low speed, gradually add powdered sugar, scraping bowl sides as needed, until fully incorporated and smooth.
  10. Finish Buttercream: Add salt and vanilla extract. If the frosting is too thick, add milk or heavy cream one tablespoon at a time until the desired consistency is reached.
  11. Level Cake Layers & Secure Base: If the cakes have domes, use a serrated knife to level them. Place a dab of frosting onto a cake board and secure the first layer.
  12. Pipe Frosting Ring & Add Mousse: Fill a pastry bag with some frosting and pipe a ring around the edge of the first layer. Fill the ring’s center with the prepared copycat Costco vanilla mousse.
  13. Add Second Cake Layer: Carefully place the second cake layer on top of the mousse-filled base.
  14. Frost the Cake: Spread the buttercream evenly over the top and sides of the cake using an offset spatula. Remove excess frosting for a smooth finish.
  15. Decorate: Finish by decorating the cake with remaining buttercream and garnish with sprinkles for a festive look. Slice and enjoy your homemade Costco vanilla cake!

Notes

  • Ensure all ingredients are at room temperature for best mixing results.
  • Softened butter is key to achieving the proper texture for both cake and buttercream.
  • Do not overbake cake layers; cake will dry if left too long in the oven.
  • For the best mousse filling, prepare it ahead of time so it sets well before assembling.
  • Wrap and chill cooled cake layers if assembling the next day to make frosting easier.
  • Use an offset spatula for smooth frosting application and a serrated knife for leveling cake domes.
  • Adjust milk or cream in buttercream gradually to avoid overly thin frosting.

Keywords: Costco vanilla cake, copycat cake recipe, vanilla layer cake, buttercream frosting, vanilla mousse cake, homemade vanilla cake, birthday cake

Find it online: https://www.sanacooks.com/copycat-costco-vanilla-cake-recipe/