Keto Peanut Butter Cookie Cake

February 2, 2025

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Keto Peanut Butter Cookie Cake is thick, soft, and delectably chewy. With a rich chocolate frosting, it’s a dream dessert for peanut butter lovers.

If you love keto peanut butter cookies, then this easy Keto Cookie Cake is going to be your newest obsession. It really is like a giant cookie baked in a pan. Decorated with some luscious keto chocolate frosting, it has instant appeal to kids and adults alike.

And believe me when I say that it tastes as good as it looks! I have a lot of chocolate peanut butter recipes. You might say I am somewhat obsessed with the flavor combination, and you wouldn’t be wrong. I know many of my readers feel the same way. That’s why my famous Keto Peanut Butter Bars and Keto Peanut Butter Pie are so crazy popular.

I also adore creating new recipes with those flavors. There is no end to the deliciousness that I can come up with. And this Keto Peanut Butter Cookie Cake is my latest offering. You’ve got to give it a try!

A Keto Peanut Butter Cookie Cake on a white cake stand with orange flowers in the background.

Why you’ll love this recipe

Moist and tender: I used all of my best tricks to make a truly tender giant cookie. As long as you don’t over-bake it!
Bursting with flavor: With plenty of peanut butter, brown sugar substitute, and chocolate chips, this really tastes like a giant cookie.
Easy to make: Pressing dough into a pan is easier than forming individual cookies. And it’s certain far easier than making a big layer cake.
Perfect for parties: Need an easy birthday treat? Or something for the office party? This cookie cake is sure to please.
Healthier dessert: Best of all, this sweet treat has only 4.5g net carbs per serving.

Ingredients you need

Top down image of ingredients for Keto Peanut Butter Cookie Cake

Creamy natural peanut butter: Choose a sugar-free peanut butter to keep the carb count low. Many natural peanut butters tend to separate, so blend it well before adding it to the cake batter.
Almond flour: Blanched almond flour helps make this cookie cake tender and moist.
Sweetener: I recommend a brown sugar substitute for this recipe, for the best flavor.
Collagen: A little collagen is what makes this cookie so deliciously tender and chewy.
Sugar-free chocolate chips: You can use whatever brand you like best. For the frosting, make sure it’s a brand that melts well.
Cream cheese: This gives the frosting some structure without having to add tons of powdered sweetener.
Heavy whipping cream: This helps thin the frosting so it easier to pipe onto the cake.
Peanuts: I garnish the cake with some chopped peanuts. It’s a great way to hide a bad piping job! But it’s entirely optional.
Kitchen staples: Butter, egg, vanilla extract, baking powder, and salt.

Step by Step Directions

A collage of 6 images showing how to make Keto Peanut Butter Cookie Cake.

Combine the wet ingredients: Beat the peanut butter, butter, and sweetener until creamy. Beat in the egg and vanilla extract until well combined.
Add the dry ingredients: Mix in the almond flour, collagen protein, baking powder, and salt and beat until just combined. Stir the chocolate chips in by hand.
Bake the cake: Grease an 8-inch round cake pan, preferably one with a removable bottom. Line the bottom of the pan with a circle of parchment and grease the parchment. Spread the batter evenly into the pan and bake at 325ºF for 20 to 25 minutes, until the center is puffed and the edges are golden brown. It will still be very soft. Remove and let cool in the pan.
Remove from the pan: Once cool, run a sharp knife around the edges to loosen and remove the sides of the pan. If your pan does not have a removable bottom or sides, you will need to carefully flip it out onto a plate, and then flip it back right-side up.
Make the frosting: Melt the chocolate chips in the microwave in 30 second increments, stirring until smooth. Set aside to cool a few minutes. Beat the butter and cream until smooth. Beat in the powdered sweetener, then beat in the vanilla extract. Beat in the melted chocolate until well combined. Add the cream and beat until just combined.
Decorate the cake: Transfer to a piping bag fitted with a star tip. Pipe decoratively around the edges of the cookie cake. Sprinkle with chopped peanuts, if desired.

A slice of Keto Peanut Butter Cookie Cake being held up on a cake server, above the rest of the cake.

Tips for Success

I specify a pan with a removable bottom for this recipe. This makes it easier to get the cookie out of the pan and onto a serving plate more easily. It can be a springform pan or a standard cake pan that has a removable bottom. If you don’t have any such thing, you can use a regular cake pan but you MUST grease it very well and line it with a circle of parchment. Then you will need to flip your cake out AFTER it is completely cool and firm.

If you are a lousy cake decorator like me, sprinkling your very uneven piped frosting with some chopped peanuts hides all the mistakes!

Don’t want to add the collagen protein? You can use another 1/3 cup of almond flour. It won’t be as chewy and tender!

Nut-Free Option: You can use sunflower seed flour in place of the almond flour, but you need to remember to add a tablespoon of acid (lemon juice) to offset the green reaction.

Sweetener Options: You can use any granular sweetener in the cookie but if you choose one that contains allulose, it may cook and brown much faster. You do need a powdered sweetener for the frosting.

Close up shot of a slice of Keto Peanut Butter Cookie Cake on a white plate with a forkful taken out of it.

Frequently Asked Questions

Can you bake this in a pie plate?

You can also bake this giant peanut butter cookie in a glass or ceramic pie plate. Do note that it will take longer to bake through. I recommend reducing the oven temperature by 25 degrees and baking it for 5 to 10 minutes longer. You won’t be able to remove it from the pan before serving.

How do you store keto cookie cake?

This keto peanut butter cookie cake can be kept on the counter for 3 days and in the fridge for a week. Be sure to cover it up and place plastic wrap against any cut surfaces to keep it from drying out. The cake can also be frozen for up to two months.

How many carbs are in a Keto Peanut Butter Cookie Cake?

This keto peanut butter cookie cake recipe has 8.8g of carbs and 4.3g of fiber per serving. That comes to 4.5g net carbs per slice.

A slice of Keto Peanut Butter Cookie Cake on a white plate with a fork, and a vase of orange Gerbera daises in behind.

More keto cookies you’ll love