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Copycat Costco Vanilla Cake with Vanilla Buttercream and Mousse Recipe

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★★★★★

4.8 from 78 reviews

This Copycat Costco Vanilla Cake Recipe replicates the beloved moist and fluffy vanilla cake layered with creamy buttercream and vanilla mousse. Perfect for special occasions, this easy-to-follow recipe offers a buttery crumb cake base paired with a smooth, rich buttercream frosting and a light mousse filling for the ultimate indulgence.

Ingredients

Scale

Cake Ingredients

  • 2 1/2 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

Buttercream Ingredients

  • 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

Assembly Ingredients

  • Copycat Costco Vanilla Mousse (quantity as needed)
  • Sprinkles for decoration

Instructions

  1. Prepare Cake Pans: Preheat your oven to 350°F (175°C). Spray two 8-inch cake pans with baking spray and line the bottoms with parchment paper to prevent sticking. Set aside.
  2. Mix Dry Ingredients: In a large bowl, whisk together cake flour, granulated sugar, baking powder, and salt until well combined.
  3. Add Butter: With a mixer on low speed, gradually add the very soft unsalted butter to the dry mixture. The batter will resemble a sandy texture once fully mixed, which is normal. Continue beating for 1 to 2 minutes, scraping the bowl sides and bottom to ensure even mixing.
  4. Add Eggs and Vanilla: Add egg whites gradually, one at a time, beating well after each addition. Then beat in the single egg yolk followed by the vanilla extract to incorporate flavor thoroughly.
  5. Incorporate Buttermilk: On low speed, gradually add the buttermilk in three additions, beating 1 to 2 minutes after each addition until smooth and well combined.
  6. Bake the Cakes: Evenly divide the batter between the prepared pans. Bake for about 26 to 30 minutes, until the cakes are golden on top and a toothpick inserted in the center comes out mostly clean with a few moist crumbs.
  7. Cool the Cakes: Let the cake layers cool in the pans for 5 minutes, then invert them onto wire racks to cool completely. Remove the parchment paper. For best results, if assembling later, wrap cooled cakes tightly in plastic wrap and refrigerate.
  8. Prepare Buttercream: In a small bowl, whisk together water and cornstarch until smooth and set aside. In a large bowl, beat the unsalted butter and vegetable shortening on medium speed until light and fluffy, about 3 to 4 minutes. Add the cornstarch mixture and mix to combine thoroughly.
  9. Add Powdered Sugar: Gradually add powdered sugar while mixing on low speed. Scrape down the sides and bottom of the bowl as needed to incorporate everything evenly.
  10. Season and Adjust Consistency: Add salt and vanilla extract. If frosting seems too thick, add milk or heavy cream one tablespoon at a time until desired spreading consistency is achieved.
  11. Level and Assemble Cake: If the cake layers have domes, use a serrated knife to level the tops for an even stacking surface. Place a small amount of frosting on a cake board to secure the first cake layer.
  12. Pipe Frosting Ring and Fill Mousse: Fill a pastry bag with some buttercream and pipe a ring around the edge of the first cake layer. Spoon in or pipe the Copycat Costco Vanilla Mousse inside the ring evenly.
  13. Stack and Frost: Place the second cake layer on top of the mousse filling. Spread the remaining buttercream evenly over the entire cake, using an offset spatula to smooth and remove any excess frosting.
  14. Decorate and Serve: Garnish the cake with sprinkles as desired. Slice and enjoy this delicious, creamy vanilla cake that rivals the famous Costco version!

Notes

  • Ensure all ingredients like eggs, butter, and buttermilk are at room temperature to achieve the best texture and rise.
  • Softened butter should be soft but not melted; this helps achieve the proper batter consistency.
  • Use cake flour for a tender crumb; if unavailable, substitute with all-purpose flour minus 2 tablespoons per cup.
  • Wrap and refrigerate the cake layers if assembling the next day to make decorating easier.
  • The mousse filling is essential for authenticity and adds lightness to the dense buttercream layers.
  • Adjust milk or cream quantity in the buttercream to suit your frosting consistency preference.
  • For added stability, chill the assembled cake for an hour before serving.

Keywords: Costco vanilla cake, copycat cake recipe, vanilla buttercream cake, homemade vanilla cake, layered vanilla cake, easy vanilla cake, buttercream frosting

Find it online: https://annakocht.com/copycat-costco-vanilla-cake-with-vanilla-buttercream-and-mousse-recipe/