I never thought a homemade vanilla cake could rival Costco’s famous bakery favorite, but this copycat version is shockingly close. One slice and you’ll see why it never lasts long.

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I’m obsessed with this Copycat Costco Vanilla Cake because it hits that big-box bakery craving without making me buy a sheet cake the size of my kitchen table. I love the soft, plush crumb, the sweet vanilla flavor, and that thick, nostalgic frosting situation that I absolutely scrape from the plate.

Cake flour keeps it tender, while sour cream gives it that rich bite I crave in a vanilla cake. And the frosting?

Ridiculous in the best way. I like a slice cold from the fridge, fork straight in, no ceremony.

Just sweet, fluffy, grocery-store birthday cake energy at home.

Ingredients

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Cake flour keeps the crumb soft and fluffy, like the Costco slice everyone fights over.
Sugar brings sweetness and helps that golden, bakery-style tenderness happen.
Baking powder gives the cake lift, so it’s not dense or sad.
Salt keeps the sweetness in check.
Tiny thing, big job.
Butter adds rich flavor and that classic homemade cake vibe.
Oil keeps each bite moist, even after chilling in the fridge.
Milk loosens the batter and helps everything bake up smooth.
Sour cream adds tang and makes the cake super tender.
Eggs give structure, so the cake slices cleanly instead of crumbling.
Vanilla is the main character here, sweet, warm, and nostalgic.
Buttermilk adds softness and a little bakery-style tang.
Warm water helps the batter blend without getting too heavy.
Frosting butter brings flavor, while shortening gives that sturdy Costco-style finish.
Powdered sugar makes the frosting sweet, fluffy, and thick enough to pipe.
Plus, cream, vanilla, and salt make the frosting smooth, balanced, and not boring.

Ingredient Quantities

3 cups cake flour, sifted

2 1/2 cups granulated sugar

1 tablespoon baking powder

1 teaspoon fine salt

1 cup unsalted butter, softened

1/2 cup vegetable oil

1 cup whole milk, room temperature

1 cup sour cream, room temperature

4 large eggs, room temperature

2 teaspoons pure vanilla extract

1/2 cup buttermilk, room temperature

1/4 cup warm water

Frosting: 1 cup unsalted butter, softened

Frosting: 1 cup vegetable shortening

Frosting: 8 to 10 cups powdered sugar, sifted

Frosting: 2 to 4 tablespoons heavy cream or whole milk

Frosting: 2 teaspoons pure vanilla extract

Frosting: 1/2 teaspoon fine salt

How to Make this

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1. Preheat oven to 350 F and grease and flour two 9 inch round pans or line with parchment; set aside.

2. Whisk together 3 cups sifted cake flour, 1 tablespoon baking powder, and 1 teaspoon fine salt in a bowl.

3. In a large bowl, beat 1 cup softened unsalted butter with 2 1/2 cups granulated sugar until light and fluffy, about 3 to 4 minutes; add 1/2 cup vegetable oil and beat until combined.

4. Add 4 room temperature large eggs one at a time, mixing well after each, then stir in 2 teaspoons pure vanilla extract.

5. In a separate measuring cup, combine 1 cup whole milk, 1/2 cup buttermilk, and 1/4 cup warm water.

6. Alternately add the dry ingredients and the milk mixture to the butter mixture in three additions, beginning and ending with the dry ingredients, mixing on low until just combined. Fold in 1 cup room temperature sour cream until batter is smooth.

7. Divide batter evenly between prepared pans and smooth tops. Bake 25 to 30 minutes, or until a toothpick inserted into the center comes out clean. Cool in pans 10 minutes, then turn out to a wire rack and cool completely.

8. For the frosting, beat 1 cup softened unsalted butter and 1 cup vegetable shortening together until smooth and pale.

9. Gradually add 8 to 10 cups sifted powdered sugar, about 2 cups at a time, mixing on low, then add 2 teaspoons pure vanilla extract, 1/2 teaspoon fine salt, and 2 to 4 tablespoons heavy cream or whole milk to reach spreadable consistency; beat on high 2 to 3 minutes until very fluffy.

10. Level cake layers if needed, spread a layer of frosting between the layers, then frost the top and sides. Chill briefly to set, then slice and serve.

Equipment Needed

1. Two 9 inch round cake pans, greased and floured or lined with parchment
2. Stand mixer or handheld electric mixer with paddle and whisk attachments
3. Set of mixing bowls, at least one large and one medium
4. Dry ingredient sifter or fine mesh sieve
5. Measuring cups and spoons for dry and liquid ingredients
6. Rubber spatula for folding and scraping bowls
7. Whisk for combining dry ingredients and liquids
8. Wire cooling rack
9. Toothpick or cake tester
10. Offset spatula or bench scraper for spreading and smoothing frosting

FAQ

Q: Can I substitute all butter for the vegetable oil or vice versa? A: The recipe uses both for tenderness and flavor; you can swap up to half of the butter for oil, but replacing all of one will change texture and flavor. If using only butter, expect a slightly firmer crumb; only oil yields a very tender but less flavorful cake.

Q: Why does the batter call for sour cream and buttermilk? A: Sour cream adds richness and moisture while buttermilk provides acidity for tender crumb and better rise when combined with baking powder. Together they create the moist, tender texture typical of this cake.

Q: How long and at what temperature should I bake it for layered pans? A: Bake in 8 or 9 inch pans at 325 F. 25 to 30 minutes for 9 inch pans, 30 to 35 for 8 inch, or until a toothpick comes out clean and edges pull slightly from the pan. Oven times vary so check early.

Q: The frosting seems very sweet. How can I adjust consistency and sweetness? A: Reduce powdered sugar slightly or add more butter and a tablespoon of cream to mellow sweetness. For stiffer frosting add more powdered sugar, for lighter and creamier add 1 to 2 tablespoons of cream at a time until desired texture.

Q: Can I make the cake or frosting ahead and how do I store them? A: Bake layers 1 to 2 days ahead, wrap tightly and refrigerate, or freeze layers for up to 2 months. Frosting keeps in the refrigerator for up to 1 week; bring to room temperature and re-whip before using. Assembled cake is best within 2 to 3 days refrigerated.

Q: Why is warm water called for in the batter? A: Warm water helps dissolve sugar and bloom the vanilla and can slightly loosen the batter for better incorporation, giving a smoother crumb and more even rise.

Copycat Costco Vanilla Cake Recipe Substitutions and Variations

Cake flour: Substitute 3 cups all purpose flour minus 6 tablespoons, then add 6 tablespoons cornstarch; sift together before measuring for lighter texture.
Vegetable oil (cake): Use 1 cup melted unsalted butter for richer flavor, or 1 cup light olive oil or canola oil for similar moisture and neutral taste.
Sour cream: Replace with equal parts full fat Greek yogurt for tang and thickness, or use Crème fraîche for slightly richer flavor.
Vegetable shortening (frosting): Use equal parts unsalted butter for flavor (expect slightly softer frosting), or use a 1:1 blend of butter and palm shortening or stabilized coconut oil for similar structure and spreadability.

Pro Tips

1. Let everything come to room temperature well before you start, especially the eggs, milk, and sour cream. They blend more smoothly and help the batter trap air for a taller, more tender cake.

2. Cream the butter and sugar until noticeably pale and fluffy, about 3 to 4 minutes. It may seem long, but those extra minutes add lift and lightness to the crumb.

3. When adding the dry and wet mixtures, keep the mixer speed low and stop as soon as you no longer see streaks of flour. Overmixing will tighten the gluten and make the cake dense.

4. Chill the frosted cake briefly for 20 to 30 minutes before slicing; it firms the frosting so you get cleaner, neater slices and fewer crumbs in the icing.

Copycat Costco Vanilla Cake Recipe

Recipe by Samantha Dalling

0.0 from 0 votes

I never thought a homemade vanilla cake could rival Costco’s famous bakery favorite, but this copycat version is shockingly close. One slice and you’ll see why it never lasts long.

Servings

servings

Calories

1248

kcal

Equipment: 1. Two 9 inch round cake pans, greased and floured or lined with parchment
2. Stand mixer or handheld electric mixer with paddle and whisk attachments
3. Set of mixing bowls, at least one large and one medium
4. Dry ingredient sifter or fine mesh sieve
5. Measuring cups and spoons for dry and liquid ingredients
6. Rubber spatula for folding and scraping bowls
7. Whisk for combining dry ingredients and liquids
8. Wire cooling rack
9. Toothpick or cake tester
10. Offset spatula or bench scraper for spreading and smoothing frosting

Ingredients

3 cups cake flour, sifted
2 1/2 cups granulated sugar
1 tablespoon baking powder
1 teaspoon fine salt
1 cup unsalted butter, softened
1/2 cup vegetable oil
1 cup whole milk, room temperature
1 cup sour cream, room temperature
4 large eggs, room temperature
2 teaspoons pure vanilla extract
1/2 cup buttermilk, room temperature
1/4 cup warm water
Frosting: 1 cup unsalted butter, softened
Frosting: 1 cup vegetable shortening
Frosting: 8 to 10 cups powdered sugar, sifted
Frosting: 2 to 4 tablespoons heavy cream or whole milk
Frosting: 2 teaspoons pure vanilla extract
Frosting: 1/2 teaspoon fine salt

Directions

Preheat oven to 350 F and grease and flour two 9 inch round pans or line with parchment; set aside.
Whisk together 3 cups sifted cake flour, 1 tablespoon baking powder, and 1 teaspoon fine salt in a bowl.
In a large bowl, beat 1 cup softened unsalted butter with 2 1/2 cups granulated sugar until light and fluffy, about 3 to 4 minutes; add 1/2 cup vegetable oil and beat until combined.
Add 4 room temperature large eggs one at a time, mixing well after each, then stir in 2 teaspoons pure vanilla extract.
In a separate measuring cup, combine 1 cup whole milk, 1/2 cup buttermilk, and 1/4 cup warm water.
Alternately add the dry ingredients and the milk mixture to the butter mixture in three additions, beginning and ending with the dry ingredients, mixing on low until just combined. Fold in 1 cup room temperature sour cream until batter is smooth.
Divide batter evenly between prepared pans and smooth tops. Bake 25 to 30 minutes, or until a toothpick inserted into the center comes out clean. Cool in pans 10 minutes, then turn out to a wire rack and cool completely.
For the frosting, beat 1 cup softened unsalted butter and 1 cup vegetable shortening together until smooth and pale.
Gradually add 8 to 10 cups sifted powdered sugar, about 2 cups at a time, mixing on low, then add 2 teaspoons pure vanilla extract, 1/2 teaspoon fine salt, and 2 to 4 tablespoons heavy cream or whole milk to reach spreadable consistency; beat on high 2 to 3 minutes until very fluffy.
Level cake layers if needed, spread a layer of frosting between the layers, then frost the top and sides. Chill briefly to set, then slice and serve.

Notes

Below you’ll find my best estimate of this recipe’s nutrition facts. Treat the numbers as a guide rather than a rule—great food should nourish both body and spirit. Figures are approximate, and the website owner assumes no liability for any inaccuracies in this recipe.