Copycat Costco Peanut Butter Pie Recipe

Peanut butter pie surrounded by bowls of graham cracker crumbs, chocolate chips, and peanut butter

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Costco's bakery is famous for churning out beloved sweet treats, ranging from the widely-praised tuxedo mousse cake to classic chocolate chunk cookies. And, if my recreation of Costco's peanut butter pie recipe has proven anything, it's that the store's bakery department definitely knows a thing or two about crafting a delicious dessert: I see why there's a run on these pies at Costco. This pie features layers of both peanut butter mousse and chocolate mousse, resulting in a positively decadent treat that's just as good — if not even better — than the Costco version.

As with any layered mousse pie, this Costco creation required a good amount of patience. It's not a particularly difficult pie to make, and in fact, it requires very little actual cooking or baking, but it does involve time spent waiting for the layers to set and firm before diving in (I will admit that there were many samples taste-tested during assembly). I can say with certainty that the resulting pie is well worth the wait, and if you break it down into more manageable steps or even prep certain elements the night before, you'll be good as gold when it comes time to serve.

I followed Costco's lead here as much as possible in terms of execution and ingredients, with a few exceptions. I went with dark chocolate instead of milk chocolate, which provided a more bitter-sweet balance to the already pretty sweet peanut butter layer. I also used marshmallows in the chocolate layer, which added sweetness, making dark chocolate the perfect choice to provide bitter notes and help make for a balanced, Costco-worthy copycat creation.

Gather the ingredients for copycat Costco peanut butter pie

This pie features a graham cracker crust, so to make it, you'll start with graham cracker crumbs, granulated sugar, and melted butter. Next, you'll prepare a plain whipped cream base, which you'll eventually divvy up to use in both the peanut butter and chocolate mousse layers.

Speaking of those mousse layers, for the PB one, you'll need softened cream cheese, creamy peanut butter, vanilla extract, powdered sugar, and half of the whipped cream mentioned above. You'll also set some of the peanut butter cream mixture aside to garnish the pie. Finally, for the chocolate mousse layer, you'll need mini marshmallows, dark chocolate chips, and heavy cream (along with the remaining pre-made whipped cream portion).

Step 1: Preheat the oven

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Preheat the oven to 375 F.

Step 2: Add the crust ingredients to a bowl

Graham cracker crust ingredients in bowl

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Make the crust by placing the crushed graham crackers, granulated sugar, and melted butter in a large bowl.

Step 3: Stir to combine the crust ingredients

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Stir until combined and the mixture resembles wet sand.

Step 4: Set some of the crust mixture aside

Graham cracker crumbs in bowl and in small measuring cup

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Remove ¼ cup of the crust mixture and set it aside.

Step 5: Transfer the crust to a pie pan

Graham cracker crumbs in bowl and in pie dish

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Transfer the crust mix to a 9-inch pie pan.

Step 6: Bake the crust

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Firmly press the mix into the bottom and sides of the pan. Place in the oven and bake for 10 minutes.

Step 7: Cool the crust

Graham cracker crust in pie dish on wire rack

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Remove the crust from the oven and set aside on a wire rack to cool completely.

Step 8: Add the heavy cream to a stand mixer bowl

Heavy cream in stand mixer bowl next to whisk attachment

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Place the heavy cream in the bowl of a stand mixer fitted with the whisk attachment.

Step 9: Whip the heavy cream

Whipped cream in bowl with whisk attachment

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Beat until stiff peaks form.

Step 10: Divide the whipped cream

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Divide the whipped cream in half, cover, and refrigerate until ready to use.

Step 11: Add the cream cheese and peanut butter to mixing bowl

Cream cheese and peanut butter in mixing bowl

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Wipe the mixing bowl clean and add the softened cream cheese and peanut butter.

Step 12: Combine the cream cheese and peanut butter

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Beat until smooth and combined.

Step 13: Mix in powdered sugar and vanilla

Powdered sugar and peanut butter in mixing bowl

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Add the powdered sugar and vanilla to the bowl and beat until combined.

Step 14: Add the whipped cream

Peanut butter and whipped cream in bowl next to smaller bowl of whipped cream

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Working in batches, fold one of the whipped cream portions into the creamy peanut butter mixture.

Step 15: Fold to combine

Peanut butter whipped cream mixture in bowl

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Fold and gently stir until combined.

Step 16: Add some peanut butter mousse to a piping bag

Peanut butter mousse in piping bag on plate

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Transfer 1 ½ cups of the peanut butter mixture to a piping bag fitted with a large fluted tip. Refrigerate until ready to use.

Step 17: Add peanut butter mousse to the pie crust

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Spoon the remaining peanut butter mixture into the cooled crust.

Step 18: Refrigerate the peanut butter mousse layer

Peanut butter mousse pie covered with plastic wrap

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Spread out evenly, cover, and refrigerate for 30 minutes.

Step 19: Add marshmallows, chocolate chips, and cream to a pan

Dark chocolate chips and mini marshmallows in saucepan

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To make the chocolate filling, place the marshmallows, chocolate chips, and heavy cream in a medium saucepan.

Step 20: Heat the chocolate mixture until combined

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Warm over low heat, stirring frequently, until melted and combined. (The mixture will resemble fudge).

Step 21: Set the chocolate mixture aside to cool

Thick chocolate mixture in bowl next to whipped cream in bowl

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Transfer the chocolate mixture to a large bowl and set aside to cool for 5 minutes.

Step 22: Fold the remaining whipped cream into the chocolate mixture

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Working in batches, fold the remaining whipped cream portion into the chocolate mixture.

Step 23: Add the chocolate mousse to the pie

Chocolate mousse mixture on top of peanut butter layer in pie crust

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Spoon the chocolate mixture over the peanut butter layer.

Step 24: Spread the chocolate mousse evenly

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Spread out evenly.

Step 25: Refrigerate the pie

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Return to the refrigerator, covered, and chill for 6 hours or until firm and set.

Step 26: Pipe the reserved peanut butter mousse on the pie

Chocolate mousse pie with peanut butter mousse piping on top

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Once set, pipe the reserved peanut butter mixture around the edge of the pie. (Remove the mixture from the fridge a few minutes before piping to soften slightly.)

Step 27: Sprinkle on the reserved graham cracker crumbs before serving

Chocolate peanut butter mousse pie with graham cracker crumbs next to small bowl of crumbs

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Sprinkle the piped edge with some of the reserved crust mixture before slicing and serving.

What can I serve with peanut butter pie?

Copycat Costco Peanut Butter Pie Recipe

Our copycat Costco peanut butter pie combines decadent layers of rich and creamy chocolate and peanut butter mousse in a buttery graham cracker crust.

Slices of chocolate peanut butter pie with whole pie in back

Total time: 6 hours, 55 minutes

For the crust
2 ½ cups crushed graham crackers
3 tablespoons granulated sugar
8 tablespoons salted butter, melted
2 cups heavy cream
:::For the peanut butter filling:
1 package (8 ounces) cream cheese, softened
¾ cup creamy peanut butter
1 cup powdered sugar
1 teaspoon vanilla extract
For the chocolate filling
2 cups mini marshmallows
1 cup dark chocolate chips
¼ cup heavy cream

Preheat the oven to 375 F.
Make the crust by placing the crushed graham crackers, granulated sugar, and melted butter in a large bowl.
Stir until combined and the mixture resembles wet sand.
Remove ¼ cup of the crust mixture and set it aside.
Transfer the crust mix to a 9-inch pie pan.
Firmly press the mix into the bottom and sides of the pan. Place in the oven and bake for 10 minutes.
Remove the crust from the oven and set aside on a wire rack to cool completely.
Place the heavy cream in the bowl of a stand mixer fitted with the whisk attachment.
Beat until stiff peaks form.
Divide the whipped cream in half, cover, and refrigerate until ready to use.
Wipe the mixing bowl clean and add the softened cream cheese and peanut butter.
Beat until smooth and combined.
Add the powdered sugar and vanilla to the bowl and beat until combined.
Working in batches, fold one of the whipped cream portions into the creamy peanut butter mixture.
Fold and gently stir until combined.
Transfer 1 ½ cups of the peanut butter mixture to a piping bag fitted with a large fluted tip. Refrigerate until ready to use.
Spoon the remaining peanut butter mixture into the cooled crust.
Spread out evenly, cover, and refrigerate for 30 minutes.
To make the chocolate filling, place the marshmallows, chocolate chips, and heavy cream in a medium saucepan.
Warm over low heat, stirring frequently, until melted and combined. (The mixture will resemble fudge).
Transfer the chocolate mixture to a large bowl and set aside to cool for 5 minutes.
Working in batches, fold the remaining whipped cream portion into the chocolate mixture.
Spoon the chocolate mixture over the peanut butter layer.
Spread out evenly.
Return to the refrigerator, covered, and chill for 6 hours or until firm and set.
Once set, pipe the reserved peanut butter mixture around the edge of the pie. (Remove the mixture from the fridge a few minutes before piping to soften slightly.)
Sprinkle the piped edge with some of the reserved crust mixture before slicing and serving.