Costco Tuxedo Cake Copycat Recipe

Costco’s tuxedo cake is one of those bakery items people genuinely miss when it’s out of stock. This copycat version gives you the same layers of chocolate cake, white chocolate mousse, and dark chocolate ganache at home, with no membership required.

It takes a bit of time, but none of the steps are complicated. Make it on a Saturday and you’ll have a showstopper dessert ready for Sunday dinner.

Why I Love This Recipe

The ganache sets firm enough to slice cleanly but stays glossy on top, which makes every piece look like it came from a proper bakery.

The white chocolate mousse is the part that really makes it work. It’s light enough that the cake doesn’t feel heavy, but rich enough that one slice is satisfying.

This is the version I keep coming back to when I need a cake that looks impressive without requiring pastry school skills.

Recipe Ingredients

• 2 cups all-purpose flour – Standard protein level gives the right crumb structure; bread flour will make it too dense
• 2 cups granulated sugar – Sweetens the batter; don’t swap for brown sugar or the moisture balance changes
• 3/4 cup unsweetened cocoa powder – Dutch-process gives a darker, less bitter flavor; natural cocoa works too
• 2 tsp baking soda – Leavening for the cocoa-based batter; check it’s fresh before using
• 1 tsp baking powder – Works alongside the baking soda for an even rise
• 1 tsp fine salt – Balances the chocolate; don’t skip it
• 2 large eggs – Room temperature; they incorporate more evenly into the batter
• 1 cup buttermilk – Keeps the crumb moist and tender; see Variations for a swap
• 1 cup hot strong brewed coffee – Deepens the chocolate flavor without tasting like coffee; don’t skip it
• 1/2 cup neutral oil – Vegetable or canola; keeps the cake moist longer than butter would
• 2 tsp vanilla extract – Rounds out the chocolate notes
• 200g (7 oz) good-quality white chocolate – Chips work in a pinch, but a bar chopped finely melts more smoothly
• 2 cups heavy whipping cream, divided – 1/2 cup goes into the mousse base, 1 1/2 cups get whipped; must be cold
• 1 tsp unflavored gelatin powder – Stabilizes the mousse so it holds its shape when sliced
• 1 tbsp cold water – To bloom the gelatin
• 200g (7 oz) dark chocolate (60 to 70% cacao) – Good ganache needs good chocolate; avoid chips for this
• 3/4 cup heavy cream – For the ganache; this is separate from the 2 cups listed above
• 2 tbsp unsalted butter – Stirred into the ganache at the end for gloss and smoothness

Variations / Substitutions

• No buttermilk – Stir 1 tbsp white vinegar into 1 cup whole milk and let it sit for 5 minutes; the texture comes out nearly identical.
• Dairy-free mousse – Full-fat coconut cream whips well and pairs nicely with dairy-free white chocolate, though the mousse will have a mild coconut flavor.
• Milk chocolate ganache – Use milk chocolate instead of dark for a sweeter, milder top layer; reduce the cream to 1/2 cup so the ganache sets firmly enough to slice.
• Extra chocolate flavor – Add 1 tsp espresso powder directly to the cake batter along with the dry ingredients to push the chocolate forward.
• No gelatin – Skip the gelatin and use 1 tbsp cornstarch whisked into the heated cream instead; the mousse will be slightly less stable but still holds for a few hours.

If you like layered chocolate desserts, you might also enjoy a Costco chocolate mousse cake recipe.

How To Make Tuxedo Cake

Step 1: Bake the Chocolate Cake Layers

Heat your oven to 350°F (175°C) and grease two 9-inch round cake pans, then line the bottoms with parchment. In a large bowl, whisk together the 2 cups flour, 2 cups granulated sugar, 3/4 cup cocoa powder, 2 tsp baking soda, 1 tsp baking powder, and 1 tsp salt until evenly combined. In a separate bowl or large measuring jug, whisk the 2 eggs, 1 cup buttermilk, 1/2 cup oil, and 2 tsp vanilla, then stir in the 1 cup hot coffee. Pour the wet mixture into the dry ingredients and whisk until smooth; the batter will be quite thin, which is normal.

Divide the batter evenly between the 2 pans and bake for 32 to 35 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs. Set the pans on a wire rack and let the layers cool completely in the pans before you try to remove them. Rushing this step leads to broken layers, so give them at least 1 hour.

Step 2: Build the White Chocolate Mousse

Sprinkle the 1 tsp gelatin over the 1 tbsp cold water in a small bowl and let it bloom for 5 minutes while you get the chocolate ready. Heat the 1/2 cup heavy cream in a small saucepan over medium-low heat until it just begins to steam, about 3 minutes. Remove from heat, add the 200g chopped white chocolate, and let it sit for 2 minutes, then stir until completely smooth. Stir the bloomed gelatin into the warm chocolate mixture until it dissolves, then let this base cool to room temperature, about 20 minutes.

While the base cools, whip the 1 1/2 cups cold heavy cream with a hand or stand mixer on medium-high speed until you get stiff peaks, about 3 to 4 minutes. Once the white chocolate base has cooled, fold a large spoonful of the whipped cream into it to lighten the texture, then fold in the rest in two more additions. Work gently so you don’t deflate it; you want it to stay airy. Refrigerate the mousse for 20 minutes until it firms up slightly before you assemble.

Step 3: Assemble the Cake Layers

Place one cooled cake layer on your serving plate or cake board. Spoon all of the white chocolate mousse onto the top of the first layer and spread it to the edges in an even layer with an offset spatula or the back of a large spoon. Set the second cake layer on top, pressing down very gently so the mousse reaches the edges evenly. Refrigerate the assembled cake for at least 30 minutes so the mousse sets enough to hold the weight of the ganache without sliding.

You’ll be able to see the white mousse layer peeking out between the two dark cake layers from the side, which is exactly what you want before the ganache goes on.

Step 4: Make the Dark Chocolate Ganache

Chop the 200g dark chocolate finely and place it in a heatproof bowl. Heat the 3/4 cup heavy cream in a small saucepan over medium heat until it just comes to a simmer, about 4 minutes. Pour the hot cream over the chocolate, let it sit undisturbed for 2 minutes, then stir slowly from the center outward until the ganache is completely smooth and glossy. Add the 2 tbsp unsalted butter and stir until it disappears into the ganache.

Let the ganache cool at room temperature for about 10 to 15 minutes, stirring occasionally. You want it pourable but not hot; if you pour it on while it’s too warm, it will run straight off the cake instead of sitting in a thick layer on top.

Step 5: Glaze and Garnish the Cake

Pull the assembled cake from the refrigerator. Pour the ganache slowly onto the center of the top layer and use an offset spatula to nudge it toward the edges, letting it drip naturally over the sides for that bakery-style look. Work quickly; the cold cake will start to set the ganache within a minute or two. Once the top is covered, let any remaining ganache drip points set for about 5 minutes at room temperature, then transfer the cake to the refrigerator for at least 1 hour until the ganache is firm and set.

To serve, slice with a sharp knife wiped clean between cuts, and bring each slice to the table at room temperature so the mousse layer is soft. The cross-section will show the dark cake, white mousse, and glossy ganache top in clean, distinct layers.

Recipe Tips

• Use good chocolate for the ganache. The ganache is the first thing people taste, so a bar of 60 to 70% cacao chocolate makes a real difference over standard baking chips, which contain stabilizers that can make ganache grainy.
• Chill every component before slicing. The cake slices cleanly only when the mousse and ganache are fully cold and firm. If the ganache looks set on top but the sides still feel soft, give it another 30 minutes.
• Level your cake layers if needed. If the tops of the baked layers have a dome, use a serrated knife to trim them flat before assembling. A flat base means the mousse layer sits evenly and doesn’t slide.
• Make the cake layers a day ahead. The baked layers can be wrapped tightly in plastic wrap and stored at room temperature overnight, which actually makes them easier to handle when assembling.

Bake times by cake pan (at 350°F / 175°C), checking doneness at a toothpick-clean 200°F (93°C) internal temperature:

How To Store

• Refrigerate – Cover the whole cake loosely with plastic wrap or place it in a cake box and refrigerate for up to 4 days. The mousse stays stable and the ganache keeps its gloss for the first 2 days.
• Reheating – This cake is served cold or at room temperature, not reheated. Pull individual slices from the fridge about 15 minutes before eating so the mousse softens slightly.
• Freezing – You can freeze individual slices on a parchment-lined tray until solid, then wrap each one in plastic and store for up to 6 weeks. Thaw overnight in the refrigerator.

What To Serve With Tuxedo Cake

A scoop of lightly salted vanilla ice cream works well alongside a slice because the salt cuts through the richness of the dark ganache and keeps the dessert from feeling one-note. Strong black coffee or an unsweetened espresso is the other natural pairing, since the bitterness plays off the sweet white chocolate mousse in a way that a milky latte won’t. If you’re serving this at a dinner party, a small glass of cold whole milk on the side is genuinely good; the fat in the milk coats the palate between bites and makes the chocolate flavor come through more clearly.

Frequently Asked Questions

Can I make this cake a day ahead of serving?

Yes. Assemble and glaze the whole cake the day before and refrigerate it overnight; the mousse and ganache both benefit from the extra setting time and the layers will be cleaner when sliced.

Why did my ganache turn out grainy instead of smooth?

This usually happens when the cream is too hot when it hits the chocolate, or when the mixture is stirred too aggressively before the chocolate melts. Let the hot cream sit on the chocolate for a full 2 minutes before touching it, then stir slowly from the center out.

Can I use a box cake mix for the chocolate layers?

Yes, a dark chocolate box mix baked in two 9-inch pans works fine here. The mousse and ganache do most of the heavy lifting in terms of flavor, so the layers just need to be sturdy and moist.

How do I get clean slices through the mousse layer?

Run a long, sharp knife under very hot water, wipe it dry, and slice in one downward motion without sawing. Repeat the hot water wipe between every cut.

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Tuxedo Cake Recipe

Print Recipe Pin Recipe

Prep Time 1 hour hr

Cook Time 35 minutes mins

Total Time 1 hour hr 35 minutes mins

Servings: 12 servings

Ingredients Method Notes

Ingredients

  

• 2 cups all-purpose flour
• 2 cups granulated sugar
• 3/4 cup unsweetened cocoa powder
• 2 tsp baking soda
• 1 tsp baking powder
• 1 tsp fine salt
• 2 large eggs
• 1 cup buttermilk
• 1 cup hot strong brewed coffee
• 1/2 cup neutral oil
• 2 tsp vanilla extract
• 200g (7 oz) good-quality white chocolate
• 2 cups heavy whipping cream, divided
• 1 tsp unflavored gelatin powder
• 1 tbsp cold water
• 200g (7 oz) dark chocolate (60 to 70% cacao)
• 3/4 cup heavy cream
• 2 tbsp unsalted butter

Method

 

1. Heat oven to 350°F (175°C). Whisk all dry cake ingredients together, whisk all wet ingredients separately including the hot coffee, combine, divide between 2 greased and lined 9-inch pans, and bake for 32 to 35 minutes until a toothpick comes out with a few moist crumbs. Cool completely in the pans.
2. Bloom the gelatin in the cold water for 5 minutes. Heat 1/2 cup heavy cream until steaming, pour over the chopped white chocolate, stir smooth, dissolve in the gelatin, and cool to room temperature. Whip the 1 1/2 cups cold heavy cream to stiff peaks, fold into the cooled white chocolate base in 3 additions, then refrigerate for 20 minutes.
3. Place one cake layer on a board, spread all of the white chocolate mousse on top, set the second layer on, and refrigerate for 30 minutes.
4. Chop the dark chocolate and place in a bowl. Heat the 3/4 cup heavy cream to a simmer, pour over the chocolate, rest 2 minutes, stir smooth, then stir in the 2 tbsp butter. Cool for 10 to 15 minutes.
5. Pour the ganache over the center of the chilled cake, spread to the edges, allow drips to fall naturally, and refrigerate for at least 1 hour. Slice with a hot, dry knife and serve with the white mousse layer visible in each cross-section.

Notes

The total time above does not include chilling time, which adds roughly 2 hours between mousse setting, assembly, and ganache firming. Plan to make this cake several hours before you need to serve it, or the day before. The cake layers can be baked up to a day ahead and wrapped at room temperature to keep them from drying out.