Copycat Costco Chocolate Cake Recipe

Costco Chocolate Cake Recipe is a rich, moist, and deeply satisfying dessert layered with chocolate mousse and covered in creamy chocolate frosting.

This Costco Chocolate Cake Recipe is incredibly delicious, packed with bold chocolate flavor and a soft texture that melts in the mouth. I decided to make this recipe to recreate the classic store-bought favorite at home.

My experience making it was rewarding and fun, with each layer turning out just right. The main specialty is the smooth mousse filling that elevates the entire Costco Chocolate Cake Recipe.

In this story, I’ll take you through my journey of making the ultimate homemade chocolate cake, from mixing the ingredients to that first bite of delicious indulgence. Ready to give Costco Chocolate Cake Recipe a try?

Why Do Costco Cakes Taste So Good?

Costco cakes are renowned for their exceptional taste, and there are a few key reasons why they stand out.

First, Costco uses high-quality ingredients, including rich cocoa, real butter, and fresh eggs, which contribute to their cakes’ moist and flavorful profile.

Their cakes are baked fresh and often have a homemade feel, thanks to carefully crafted recipes that balance sweetness with a tender crumb.

The frosting, typically made from a blend of butter and cream, is both creamy and indulgent, providing a perfect complement to the cake’s rich base.

How To Prepare Costco Chocolate Cake Recipe

Preparation Time: 20 minutes

Cooking Time: 35 minutes

Total Time: 55 minutes

Calories: 320

Course: Dessert

Cuisine: American

Serving Size: 12

Kitchen Utensils Needed

• 2 x 9-inch round cake pans
• Mixing bowls
• Electric mixer or whisk
• Measuring cups and spoons
• Rubber spatula
• Saucepan or kettle (for boiling water)
• Cooling rack
• Serrated knife or cake leveler
• Offset spatula or frosting knife

Recipe Ingredients

For the Chocolate Cake:

• 1¾ cups all-purpose flour
• 1½ cups granulated sugar
• ¾ cup unsweetened cocoa powder
• 1½ teaspoons baking powder
• 1½ teaspoons baking soda
• 1 teaspoon salt
• 2 large eggs
• 1 cup whole milk
• ½ cup vegetable oil
• 2 teaspoons vanilla extract
• 1 cup boiling water

Chocolate Mousse Filling:

• 5.9 oz instant chocolate pudding mix
• 3 cups heavy whipping cream

Chocolate Frosting:

• 1 cup unsalted butter, softened
• 3½ cups powdered sugar
• ½ cup unsweetened cocoa powder
• ½ cup heavy cream
• 2 teaspoons vanilla extract
• Pinch of salt

How To Make Costco Chocolate Cake Recipe

1. Pan Prep and Oven Heat

Set the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, or line them with parchment paper for easy removal after baking.

2. Mix Dry Ingredients

In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt until fully combined.

3. Add Wet Ingredients

Add eggs, milk, oil, and vanilla to the dry mixture. Beat with an electric mixer on medium speed for about 2–3 minutes until the batter is smooth.

4. Add Boiling Water

Slowly stir in boiling water. The batter will be thin—this is expected. Mix until just blended, then pour evenly into the two pans.

5. Bake the Cakes

Bake for 30–35 minutes, or until a toothpick inserted in the center comes out clean. Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.

6. Make the Mousse Filling

In a large bowl, beat instant chocolate pudding mix with heavy cream on high speed until thick and mousse-like, about 3–4 minutes. Keep chilled until needed.

7. Prepare the Frosting

In another bowl, beat softened butter until smooth. Gradually add powdered sugar and cocoa powder while mixing on low. Add heavy cream, vanilla, and a pinch of salt, then beat on medium-high until fluffy about 4–5 minutes.

8. Assemble the Cake

Level cake layers if needed. Place one layer on a serving plate, spread with mousse, then place the second layer on top. Cover the cake with frosting, smoothing the top and sides. Chill for 30 minutes before slicing.

Special Note

For an extra touch, you can add chocolate shavings or sprinkles on top of the frosting. To make the cake even richer, consider incorporating a layer of chocolate ganache between the cake layers or using a flavored liqueur in the cake batter for added depth.

How Can I Decorate

Decorating a Costco chocolate cake at home is simple yet fun. Start by covering the cake with a smooth layer of chocolate frosting, ensuring it’s even and glossy.

For a professional touch, you can pipe decorative swirls or rosettes around the edges using a star-shaped piping tip.

To enhance the cake’s appearance, sprinkle a generous amount of chocolate shavings or mini chocolate chips on top.

For an added burst of flavor, consider placing fresh berries like raspberries or strawberries in the center, creating a beautiful contrast with the rich chocolate.

A dusting of powdered sugar can also give it an elegant finish. The beauty of decorating this cake is that you can get creative and make it uniquely yours!

My Tips For Making

Here are my  tips for making the perfect homemade Costco chocolate cake recipe:

1. The key to a rich, deep chocolate flavor is using a premium cocoa powder. Look for one with a strong, pure chocolate taste to enhance the overall flavor.

2. Overmixing can lead to a dense cake. Gently mix the ingredients until they’re just combined to keep the cake light and fluffy.

3. Sifting the flour, cocoa powder, and baking soda together helps to avoid clumps and ensures even distribution of dry ingredients throughout the batter.

4. Make sure your eggs, butter, and milk are at room temperature before mixing. This helps the ingredients blend more evenly for a smoother batter.

5. Adding a small amount of brewed coffee or espresso to the batter enhances the chocolate flavor without making the cake taste like coffee. It deepens the richness.

6. Allow your cake to cool completely before applying frosting. Chilling the layers helps the frosting set better and prevents it from sliding off.

7. Costco’s cake is known for its thick layer of delicious frosting. Don’t be shy—use extra frosting to cover the entire cake for that signature indulgence.

Proper Storage

To properly store your homemade Costco chocolate cake recipe, keep it in an airtight container at room temperature for up to 3-4 days.

If you need to store it longer, refrigerate it to extend its freshness for up to a week. Make sure to bring the Costco chocolate cake recipe to room temperature before serving for the best taste and texture.

If you want to store it for an extended period, you can freeze individual slices in plastic wrap or foil, then place them in a freezer bag, where it will stay fresh for up to 3 months. Just thaw at room temperature before enjoying!

Conclusion

Making the Costco Chocolate Cake Recipe at home was a truly enjoyable experience. Every layer came together beautifully, and the taste was rich, moist, and full of deep chocolate flavor.

The mousse filling added a creamy texture that made it even more special. I had fun throughout the process and felt proud of the final result.

You now understand how to make Costco Chocolate Cake Recipe, and I hope you’ll give it a try soon. Costco Chocolate Cake Recipe a treat worth making and sharing with everyone around you.