Costco Chocolate Cake is a rich and moist chocolate dessert that is loved for its soft layers and creamy chocolate frosting. This bakery-style cake is made with cocoa powder, melted chocolate, coffee, and buttermilk to create a deep chocolate flavor in every bite.
The smooth frosting adds a creamy texture that pairs perfectly with the tender cake layers. Many people enjoy serving this cake for birthdays, family gatherings, and holiday celebrations because it looks impressive and tastes amazing.
It has the perfect balance of sweetness and rich chocolate flavor without being too heavy. If you love homemade chocolate desserts, this Costco Chocolate Cake is a delicious treat worth making.
Why You’ll Love This Costco Chocolate Cake Recipe?
- Rich chocolate flavor that tastes like a bakery cake
- Super moist texture that stays soft for days
- Beginner-friendly instructions with simple steps
- Perfect for birthdays, parties, and holidays
- Creamy chocolate frosting with optional ganache
- Easy to make ahead for special occasions
- Large recipe that feeds a crowd
- Homemade version of the famous Costco chocolate cake

How to Make Costco Chocolate Cake?
Recipe Overview
Costco Chocolate Cake is a rich, moist, bakery-style chocolate cake layered with creamy chocolate frosting and optional ganache for the ultimate chocolate dessert experience.
- Prep Time: 35 minutes
- Cook Time: 40 minutes
- Total Time: 1 hour 15 minutes
- Course: Dessert
- Cuisine: American
- Difficulty: Intermediate
- Servings: 16 slices
- Calories: 780 per serving
Ingredients
For the Cake
- 2 cups freshly brewed coffee
- 4 cups sugar
- 2 cups buttermilk
- 4 cups all-purpose flour
- 1 1/2 cups Dutch-processed cocoa powder
- 1 cup sour cream or Greek yogurt
- 4 teaspoons baking soda
- 4 teaspoons vanilla extract
- 2 teaspoons baking powder
- 6 large eggs
- 1 cup vegetable oil
- 2 teaspoons sea salt
- 8 ounces dark chocolate, melted
For the Frosting
- 3 cups Dutch-processed cocoa powder
- 2 tablespoons vanilla extract
- 16 ounces cream cheese, softened
- 3 cups unsalted butter, softened
- 1/2 cup heavy whipping cream
- 12 ounces powdered sugar
- 1 teaspoon salt
For the Ganache (Optional)
- 1 1/2 cups heavy whipping cream
- 2 cups dark chocolate chips
Step-by-Step Instructions
Step 1: Prepare the Pans
Preheat your oven to 350°F (175°C). Grease and line two 9-inch cake pans with parchment paper.
Step 2: Mix the Dry Ingredients
In a large bowl, whisk together:
- Flour
- Cocoa powder
- Baking soda
- Baking powder
- Salt
Set aside.
Step 3: Mix the Wet Ingredients
In another large bowl, combine:
- Sugar
- Eggs
- Buttermilk
- Sour cream
- Vegetable oil
- Vanilla extract
Whisk until smooth.

Step 4: Add Coffee and Chocolate
Slowly stir in the hot coffee and melted dark chocolate. The batter will look thin, which is completely normal.
Step 5: Combine Everything
Gradually add the dry ingredients into the wet mixture. Stir gently until fully combined and smooth.
Step 6: Bake the Cakes
Divide the batter evenly between the prepared pans. Bake for 35–40 minutes or until a toothpick inserted into the center comes out mostly clean. Let the cakes cool in the pans for 15 minutes before transferring them to a wire rack.
Step 7: Make the Frosting
In a large bowl, beat the butter and cream cheese until fluffy.
Add:
- Cocoa powder
- Powdered sugar
- Vanilla
- Salt
- Heavy cream
Beat until creamy and smooth.
Step 8: Prepare the Ganache (Optional)
Heat the heavy cream until steaming but not boiling. Pour over the chocolate chips and let sit for 2 minutes. Stir until smooth and glossy.
Step 9: Assemble the Cake
Place one cake layer on a serving plate. Spread a thick layer of frosting on top. Add the second layer and frost the entire cake. Drizzle ganache over the top if desired.
Nutrition
- Calories: 780
- Carbohydrates: 92g
- Protein: 9g
- Fat: 42g
- Saturated Fat: 24g
- Cholesterol: 145mg
- Sodium: 540mg
- Sugar: 68g
- Fiber: 6g
Pro Tips for This Costco Chocolate Cake Recipe
1. Use room-temperature ingredients for smoother batter and frosting.
2. Don’t skip the coffee because it enhances the chocolate flavor beautifully.
3. Chill the cake layers before frosting for cleaner layers.
4. Use high-quality cocoa powder for the richest taste.
5. Avoid overmixing the batter to keep the cake soft.
6. Add ganache only after the cake is fully frosted and chilled slightly.
Variations For This Costco Chocolate Cake Recipe
Chocolate Fudge Version
Add chocolate chips between the cake layers for extra richness.
Mocha Chocolate Cake
Increase the coffee flavor with 1 teaspoon espresso powder.
Cookies and Cream Cake
Add crushed chocolate sandwich cookies into the frosting.
Salted Caramel Twist
Drizzle caramel sauce between the layers and sprinkle flaky sea salt on top.
Serving Suggestions
This Costco Chocolate Cake tastes amazing with:
- Vanilla ice cream
- Fresh strawberries
- Hot coffee
- Cold milk
- Whipped cream
- Chocolate shavings
It’s especially perfect for birthdays, holiday dinners, and family celebrations.
Storage & Reheating
1. Refrigerator
Store covered in the refrigerator for up to 5 days.
2. Freezer
Wrap slices tightly and freeze for up to 2 months.
3. Reheating
For a warm dessert, microwave a slice for 10–15 seconds before serving.
FAQs About Costco Chocolate Cake
Can I Make This Cake Ahead Of Time?
Yes. You can bake the cake layers 1–2 days ahead and frost later.
Does The Coffee Make The Cake Taste Like Coffee?
No. It simply deepens the chocolate flavor.
Can I Use Regular Cocoa Powder?
Yes, but Dutch-processed cocoa gives a richer bakery-style taste.
Can I Make Cupcakes Instead?
Absolutely. Bake cupcakes for about 18–22 minutes.
How Do I Keep The Cake Moist?
Avoid overbaking and store the cake covered tightly.
Final Thoughts
This homemade Costco Chocolate Cake is rich, moist, creamy, and loaded with deep chocolate flavor in every bite. From the soft cake layers to the smooth frosting and glossy ganache, it feels just like a bakery dessert made right in your kitchen.
Whether you’re baking for a birthday, holiday, or weekend treat, this cake is guaranteed to impress family and friends. Once you try this homemade version, you’ll want to make this Costco Chocolate Cake again and again.

Costco Chocolate Cake
Ingredients
Method
- Preheat your oven to 350°F (175°C). Grease and line two 9-inch cake pans with parchment paper.
- In a large bowl, whisk together:
- Flour
- Cocoa powder
- Baking soda
- Baking powder
- Salt
- Set aside.
- In another large bowl, combine:
- Sugar
- Eggs
- Buttermilk
- Sour cream
- Vegetable oil
- Vanilla extract
- Whisk until smooth.
- Slowly stir in the hot coffee and melted dark chocolate. The batter will look thin, which is completely normal.
- Gradually add the dry ingredients into the wet mixture. Stir gently until fully combined and smooth.
- Divide the batter evenly between the prepared pans. Bake for 35–40 minutes or until a toothpick inserted into the center comes out mostly clean. Let the cakes cool in the pans for 15 minutes before transferring them to a wire rack.
- In a large bowl, beat the butter and cream cheese until fluffy.
- Add:
- Cocoa powder
- Powdered sugar
- Vanilla
- Salt
- Heavy cream
- Beat until creamy and smooth.
- Heat the heavy cream until steaming but not boiling. Pour over the chocolate chips and let sit for 2 minutes. Stir until smooth and glossy.
- Place one cake layer on a serving plate. Spread a thick layer of frosting on top. Add the second layer and frost the entire cake. Drizzle ganache over the top if desired.