Reese’s Peanut Butter Cookie Cake

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Prepare to be obsessed with this Peanut Butter Cookie Cake. It’s a giant, moist, chewy peanut butter cookie stuffed with chocolate chips and Reese’s. As if that weren’t enough, it’s topped with chocolate buttercream and more Reese’s. Oh my!

If you love supersizing your favorite cookie recipes, definitely check out my Oreo cookie cake and this giant cinnamon roll cookie cake, too!

Why You’ll Love This Cookie Cake

• Moist and chewy. This cookie cake is so delicious to bite into. It’s perfectly moist and wonderfully chewy. Like your favorite cookie, but bigger and better.
• A classic flavor combo. I don’t know about you, but I am a sucker for anything peanut butter and chocolate. It’s one of those flavor combinations that will have you hooked at first bite and this cookie cake is all about it.
• Easy to make. This dessert is easier than a cake because there’s none of the layering and fancy icing involved. It’s also easier than cookies because you don’t have to make a bunch of dough balls! Just press all of the dough into a cake pan and bake.

Love the chocolate-peanut butter combo but looking for a more elegant dessert? Try my peanut butter chocolate layer cake! You might also like this easy Reese’s peanut butter fudge and creamy Reese’s cheesecake.

Ingredient Notes

Here’s what you’ll need to make this Reese’s peanut butter cookie cake. Be sure to scroll to the recipe card below for precise measurements.

Cookie Cake

• All-purpose flour – Be sure to measure your flour accurately. Too much flour will give you a dense, dry bread. I like using a food scale, but the spoon and level method also works.
• Baking soda – For the perfect rise and texture.
• Salt – Without a little salt, your cookie cake will be bland.
• Unsalted butter – The butter should be at room temperature. If it is too cold or too melted it won’t cream properly with the peanut butter and sugars.
• Peanut butter – Go with a smooth, creamy peanut butter. Not the natural kind.
• Granulated sugar and light brown sugar – I like using both. The brown sugar contributes a little extra moisture and depth of flavor.
• Egg – Be sure to use large eggs, not medium or extra large.
• Vanilla extract
• Chopped peanut butter cups – I love the added Reese’s, but you could always leave those out and add more chocolate chips, or even peanut butter chips.
• Semi-sweet chocolate chips – Milk or dark chocolate chips will also work.

Buttercream

• Unsalted butter – Start with room temperature butter. If it’s too cold, you’ll end up with lumpy frosting.
• Powdered sugar – The powdered sugar sweetens the frosting while also providing volume and giving it a stiff enough consistency for piping.
• Natural unsweetened cocoa powder – You can use Dutch-processed cocoa powder for a richer chocolate flavor and darker color.
• Vanilla extract
• Heavy whipping cream – You could also use milk or water, you’d just need less of it.
• Full-sized Reese’s – Cut in half to decorate.

How to Make a Reeses Peanut Butter Cookie Cake

Heat up the oven and tie on your apron. Here’s a quick overview of how to make this chocolaty, peanut buttery cookie cake. Don’t forget to scroll to the recipe card below for more detailed instructions.

To make the cookie cake

• Prep. Preheat the oven to 350°F, line the bottom of a 9-inch cake pan with parchment paper, and grease the sides.
• Combine the dry ingredients. Whisk together the flour, baking soda, and salt.
• Combine the wet ingredients. Cream together the butter, peanut butter and sugars on medium speed for 2-3 minutes. Mix in the egg and vanilla.

• Put it all together. Mix the dry ingredients into the peanut butter mixture and then stir in the Reese’s and chocolate chips.
• Bake. Press the dough evenly into the cake pan, press extra chocolate chips and/or Reese’s into the top, and bake for 18-22 minutes.

• Cool. Allow the cookie cake to cool completely in the pan.
• Transfer to a serving plate. Flip the cake upside down onto a cooling rack, place a serving plate on top, and flip it right side up.
• Make the frosting. Beat the butter until smooth. Mix in 1 cup of powdered sugar followed by the cocoa powder, vanilla, and 1 tablespoon of heavy cream. Mix in the remaining powdered sugar and more cream (if needed) to get the right consistency.
• Decorate. Pipe the buttercream around the edges of the cookie cake and garnish with Reese’s.

Recipe Tips

• Choose the right peanut butter. You’ll want to choose a smooth, creamy peanut butter as opposed to a chunky one. Also, steer clear of natural peanut butters. They separate, which can interfere with the way the ingredients for your cookie dough mix together.
• Room temperature butter. The butter in the cookie dough should be at room temperature. Otherwise it won’t cream properly with the peanut butter and sugars (see my next point). The butter in the frosting should also be at room temperature unless you want lumpy frosting. So think ahead and let your butter sit out for an hour or so before beginning.
• Don’t skimp on creaming time. When creaming together the butter, peanut butter, and sugars, do so until the mixture has significantly lightened in color and become fluffy. This process incorporates air into the dough, which helps ensure your cookie cake doesn’t turn out overly dense.
• Scrape down the sides of the bowl. When adding and mixing ingredients into the dough (and frosting), scrape down the sides of the bowl intermittently to ensure everything makes it into the dough/buttercream.
• Don’t over-mix. When mixing the dry ingredients into the wet ingredients and also when folding the Reese’s and chocolate chips into the dough, mix just until everything is incorporated. No more. Mixing past this point can cause the glutens in the flour to overdevelop and your cookie cake to turn out tough.
• Cool completely (in the pan). Allow the cookie cake to cool completely in the pan before transferring it to a serving plate and frosting. Cooling it in the pan allows it extra time to firm up so that it doesn’t fall apart. Allowing it to cool completely before adding the frosting ensures the frosting stays put on top of the cake, rather than melting off.

Fun Variations

Feel free to get creative! Here are some fun ways to throw a personalized spin on this recipe.

• Mix-in mania. I went with chocolate chips and Reese’s, but you could go with all chocolate chips or all Reese’s. Alternatively, you could swap one or both out for white chocolate chips, butterscotch chips, or peanut butter chips! A chopped candy bar would also be good. Maybe Heath Bar or Snickers? Just be sure to keep your mix-ins to about 1 1/4 cups total.
• Choose a different frosting. Not a chocolate frosting person? Try my Vanilla Buttercream or the peanut butter frosting from these Peanut Butter Cupcakes.
• Sweet additions. Just in case this peanut butter cookie cake isn’t sweet enough for you as is, go ahead and drizzle some of my Easy Homemade Hot Fudge Sauce over the top and serve your slice with a scoop of vanilla ice cream.

How to Store

• Counter/Fridge. Seal the cake in an airtight cake carrier or wrap it in a double layer of plastic wrap (use toothpicks to prop the plastic away from the frosting). Alternatively, arrange slices in a single layer in an airtight container. You can store this cookie cake at room temperature for up to 2 days. After that, pop it in the fridge for an extra 2-3 days.
• Freezer. Let the unfrosted cake firm up in the freezer for a couple of hours before wrapping the whole thing in a double layer of plastic wrap. Otherwise, arrange slices in a single layer in an airtight container. You can store it in the freezer for up to 3 months. Allow the cookie cake to thaw in the fridge before diving in.

More Reese’s Desserts

• Peanut Butter Chocolate Mousse Cake
• Reese’s Peanut Butter Pie
• Mini Reese’s Peanut Butter Cheesecakes
• Mini Reese’s Chocolate Peanut Butter Cheesecake Trifles
• Reese’s Peanut Butter Chocolate Cookie Cups
• No Bake Reese’s Peanut Butter Cheesecake
• Reese’s Peanut Butter Chocolate Cookie Sandwiches

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