Copycat Costco Sheet Cake Recipe is an indulgent, nostalgic delight that brings a taste of the iconic Costco bakery right into your kitchen. With its fluffy layers, creamy mousse filling, and rich frosting, this cake is perfect for birthdays, gatherings, or simply as a sweet treat to brighten up your day. What’s even better is that it’s an easy, step-by-step recipe that anyone can master, allowing you to recreate this beloved cake with minimal fuss. Imagine serving a slice of this comforting cake, with its moist texture and delightful sweetness, to family and friends—it’s bound to become a favorite at any celebration!
Ingredients
To create this luscious Copycat Costco Sheet Cake, you’ll need a harmonious blend of ingredients. Start with two boxes of white cake mix—the backbone of this cake, providing a light and airy foundation. A hint of kosher salt balances the sweetness, enhancing all the flavors. You’ll need eight large egg whites for that perfect rise, while 1 ½ cups of sour cream add moisture and rich creaminess. Whole milk contributes to the cake’s flavor and texture, complemented by vegetable oil for added richness and pure vanilla extract for a fragrant touch.
For the mousse filling, use cream cheese at room temperature, along with confectioners’ sugar and a pinch of kosher salt for a smooth, sweet layer. The instant vanilla pudding not only thickens the mousse but elevates the flavor, while heavy cream helps create that luxurious experience.
For the frosting, bring together vegetable shortening, water, more vanilla extract, and salt. Last but not least, incorporate eight cups of confectioners’ sugar, ensuring the frosting is as fluffy and sweet as can be. Don’t forget a sprinkle of sprinkles for the ultimate celebratory touch!
Step-by-Step Directions
Preheat your oven to 350 degrees Fahrenheit. This initial step is crucial for creating a perfectly baked cake.
Grease and line two 13×9 metal baking pans with parchment paper, ensuring easy release after baking.
In a large bowl, whisk together the cake mix and salt until well combined. This will provide a flavorful base for your cake.
Add in the egg whites, sour cream, milk, oil, and vanilla extract. Beat until the mixture is smooth and evenly mixed, achieving a delightful batter.
Divide the batter evenly between the prepared pans. Bake for 20-25 minutes, or until a toothpick inserted in the center comes out clean. Your kitchen will be filled with the sweet scent of baking cake!
Once baked, allow the cakes to cool fully in the pans before trimming the tops if necessary to ensure even stacking.
To prepare the mousse filling, beat together the cream cheese, confectioners’ sugar, and a pinch of salt until smooth. This creates a rich, creamy base for your mousse.
Gradually mix in the milk and instant pudding mix. Beat until combined, then add the heavy cream and whip until the mousse thickens to your desired consistency.
For the frosting, beat the shortening, water, vanilla extract, and salt together until smooth. Gradually add the confectioners’ sugar, mixing on low until fluffy. You’re creating a thick, sweet frosting that will elevate your cake.
To assemble the cake, place one layer of cake on your serving platter. Spread a generous amount of mousse filling on top, then layer the second cake over it. Cover the entire cake with frosting, finishing with colorful sprinkles for the perfect presentation.
Tips & Tricks
For the best results, sift the flour and sugar for the frosting and mousse to eliminate any lumps and achieve a smooth texture. If you want to personalize your cake, consider adding flavor extracts like almond or lemon to the cake batter for a unique twist. Additionally, refrigerating the mousse for a brief period before assembling the cake can help enhance its flavor. Remember to keep your frosting cool while decorating; it tends to soften at room temperature.
Serving Suggestions & Pairings
This Copycat Costco Sheet Cake is perfect for a variety of occasions—serve it at birthday parties, potlucks, or even casual family dinners. Pair it with a side of fresh fruit or a scoop of vanilla ice cream for a delightful contrast to the cake’s sweetness. For drinks, consider serving it with iced coffee, a rich hot chocolate, or even a chilled glass of your favorite fruit punch to complement the cake’s flavors.
Nutritional Information
Each slice of this Copycat Costco Sheet Cake roughly contains 320 calories, with primary sources from carbohydrates and fats. It’s important to enjoy this indulgence as part of a balanced diet—opt for fresh fruit or a salad when serving to bring a touch of nutrition to your meal.
Storing Tips & Variations
To store this cake, keep any leftovers in an airtight container at room temperature for up to three days, or refrigerate for up to a week. You can also freeze the cake for up to three months; just ensure it’s wrapped tightly in plastic wrap and aluminum foil. If you’re looking to switch things up, try different flavors of instant pudding or mix-ins, such as chocolate chips or nuts, to customize the mousse layer!
Conclusion
Now that you have this delightful Copycat Costco Sheet Cake recipe, it’s time to don your apron and get baking! This cake is not just about indulgence—it’s about creating memories in the kitchen and sharing smiles with loved ones. We hope you enjoy making and tasting it as much as we do. Don’t forget to share your experience and any tweaks you made to the recipe in the comments—we’d love to hear how it turned out for you!
FAQs
Can I use a different cake mix flavor?
Absolutely! Feel free to experiment with chocolate or lemon cake mixes for a fun twist.How do I prevent my cake from sticking to the pans?
Ensure you grease your pans thoroughly and use parchment paper. Allow the cakes to cool completely before attempting to remove them.Is it necessary to use sour cream?
Sour cream adds moisture and richness, but if you don’t have any, you can substitute with yogurt or even buttermilk.How long does this cake last once baked?
The baked cake stays fresh for up to three days at room temperature, a week in the fridge, and up to three months in the freezer.Can the frosting be made ahead of time?
Yes! You can prepare the frosting a day in advance and store it in the fridge. Just give it a good stir before using.
With these expert tips and guidelines, you’re fully equipped to whip up a stunning Copycat Costco Sheet Cake that will impress both friends and family alike! Happy baking!
Copycat Costco Sheet Cake
Ingredients
For the Cake
- 2 boxes white cake mix The backbone of the cake, providing a light and airy foundation.
- 8 large egg whites For that perfect rise.
- 1.5 cups sour cream Adds moisture and richness.
- 1 cup whole milk Contributes to the cake's flavor and texture.
- 1/2 cup vegetable oil For added richness.
- 1 tbsp pure vanilla extract For a fragrant touch.
- 1 tsp kosher salt Balances the sweetness.
For the Mousse Filling
- 8 oz cream cheese At room temperature.
- 1 cup confectioners’ sugar For a smooth, sweet layer.
- 1 tbsp instant vanilla pudding mix Thickens the mousse and elevates flavor.
- 1 cup heavy cream Helps create that luxurious experience.
- 1 pinch kosher salt
For the Frosting
- 1 cup vegetable shortening
- 1/4 cup water
- 1 tbsp vanilla extract
- 1 tsp salt
- 8 cups confectioners’ sugar Ensures the frosting is fluffy and sweet.
- to taste sprinkles For decoration.
Instructions
Preparation
- Preheat your oven to 350°F.
- Grease and line two 13x9 metal baking pans with parchment paper.
- In a large bowl, whisk together the cake mix and kosher salt until well combined.
- Add in the egg whites, sour cream, whole milk, vegetable oil, and vanilla extract. Beat until smooth.
- Divide the batter evenly between the prepared pans.
Baking
- Bake for 20-25 minutes, or until a toothpick inserted in the center comes out clean.
- Allow the cakes to cool fully in the pans before trimming for even stacking.
Mousse Filling
- Beat together the cream cheese, confectioners’ sugar, and a pinch of kosher salt until smooth.
- Gradually mix in the milk and instant pudding mix, beating until combined.
- Add the heavy cream and whip until thickened to desired consistency.
Frosting & Assembly
- Beat the shortening, water, vanilla extract, and salt together until smooth.
- Gradually add the confectioners’ sugar, mixing on low until fluffy.
- Place one layer of cake on your serving platter. Spread a generous amount of mousse filling on top, then layer the second cake over it.
- Cover the entire cake with frosting and finish with sprinkles.
