This homemade Costco-inspired chocolate cake features two layers of moist chocolate fudge cake, rich chocolate mousse filling, and smooth chocolate frosting. The cake is topped with decorative piping and chocolate crumbs. It’s rich, decadent, and deeply satisfying, offering a perfect balance of sweetness and texture.
Costco’s All-American Chocolate Cake was more than a dessert, a rich, towering celebration of chocolate in every bite. Though no longer sold in stores, this cake’s moist texture, velvety mousse, and glossy ganache frosting made it legendary among chocolate lovers. You’re in the right place if you’ve missed that indulgent experience.
Why This Copycat Recipe Works
Replicating the Costco chocolate cake requires its balance of texture, structure, and flavor. Instead of baking from scratch with flour and cocoa alone, this version uses a chocolate fudge cake mix as the base, offering consistency and deep flavor. used melted butter instead of oil, milk instead of water, and added one extra egg for richness.
From there, we layer with a luscious mousse made using instant chocolate pudding mix and heavy whipping cream, and top it off with a smooth frosting crafted from butter, powdered sugar, cocoa powder, and melted semisweet chocolate chips with corn syrup. Together, they recreate the layered, chocolate-drenched brilliance that fans remember.
Costco Chocolate Cake (Copycat Recipe)
Prep Time: 45 minutes
Cook Time: 30 minutes
Chill Time: 60 minutes
Total Time: 2 hours 15 minutes
Servings: 12 slices
Skill Level: Intermediate
Ingredients
For the Cake:
- 1 box (13.5 oz) chocolate fudge cake mix
- Eggs (as per box + 1 extra)
- ½ cup melted butter (instead of oil)
- 1 cup milk (instead of water)
For the Chocolate Mousse Filling:
- 1 box (5.9 oz) instant chocolate pudding mix
- 3 cups heavy whipping cream (cold)
For the Frosting:
- 1 cup unsalted butter (softened)
- 2 cups powdered sugar
- 1 cup unsweetened cocoa powder
- 1 tsp vanilla extract
- 4 cups semisweet chocolate chips
- ½ cup corn syrup
Method
Step 1: Preheat oven to 350°F. Grease and line two 9-inch cake pans with parchment paper.
Step 2: In a large bowl, combine cake mix, eggs, melted butter, and milk. Beat with an electric mixer until smooth.
Step 3: Divide the batter between the pans. Bake for 28–32 minutes or until a toothpick comes out clean. Cool completely.
Step 4: Slice off domed tops to level each cake layer. Optionally, crumble the tops for decoration later.
Step 5: Beat heavy cream and pudding mix in a chilled bowl until stiff peaks form. Chill the mousse for 20 minutes.
Step 6: Place the first cake layer on a platter. Spread half the mousse. Add the second cake layer. Spread the remaining mousse. Refrigerate to firm up.
Step 7: Melt chocolate chips and corn syrup in a microwave-safe bowl until smooth. In a separate bowl, beat butter, powdered sugar, cocoa powder, and vanilla. Add melted chocolate. Mix until creamy and glossy.
Step 8: Apply a thin crumb coat. Chill for 20 minutes. Then frost the entire cake evenly. Optionally, press cake crumbs on the sides.
Step 9: Use a piping bag to add swirls or borders. Chill the finished cake for at least 1 hour before slicing.
Storage Tips
- Refrigerate leftovers for up to 5 days.
- Freeze individual slices wrapped in foil and plastic for up to 3 months.
Flavor Variations Inspired by Costco’s Chocolate Cake
If you’re interested in customizing the flavor while staying close to Costco’s original structure, here are some winning ideas:
- Mocha Version: Add 1 tsp of espresso powder to the mousse or cake batter for a subtle coffee finish.
- Mint Chocolate: Use mint extract in place of vanilla in the mousse for a refreshing twist.
- Raspberry Layer: Add a thin spread of raspberry jam underneath each mousse layer for a sweet-tart contrast.
- Salted Chocolate: Sprinkle a pinch of flaky sea salt over the final ganache frosting for a gourmet touch.
Thank you.
Costco Chocolate Cake Recipe is a delicious and easy cake that can be made in a short amount of time. It is perfect for any occasion and is sure to impress your guests.