These soft & chewy peanut butter chocolate chip cookie bars are easy to make in a 9x13 pan! Add your favorite chocolate chips and mix-ins for the ultimate crowd pleaser!
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Why I Love This Peanut Butter Cookie Bars
- Soft & Chewy: No crumbly cookie here! These peanut butter cookie bars use cornstarch to make them chewy, yet perfectly sliceable.
- Perfectly Peanut Buttery: I tested this peanut butter cookie dough over 8 times while developing my peanut butter cookie cake recipe and finally achieved something that was durable and had the perfect peanut butter flavor.
- No Scooping Needed! As opposed to making individual cookies, you can simply press these into a 9x13" pan and bake. I love adapting my favorite cookie recipes into dessert bars, as it makes the process so much quicker.
Ingredient Notes & Substitutions
- Unsalted Butter: Be sure to use real butter here; not margarine! I prefer unsalted but salted will work fine, too (just omit the salt). Use room temperature butter or microwave for 10 seconds to slightly soften.
- Creamy Peanut Butter: We tested this recipe using creamy peanut butter. Natural peanut butter will be too oily and will not bake the same.
- Cornstarch: I highly recommend adding this, as it gives the cake a chewy, yet durable texture. While you can omit this, we found that the cookie cake with the cornstarch stayed softer for longer and had a slight edge in texture over the one that didn't have it.
- Semisweet Chocolate Chips & Peanut Butter Chips: I like semi-sweet chocolate chips but feel free to use the type of chocolate you like best! While you can use any kind of chips, we do recommend keeping the ratios the same (as the gooey chips help hold the dough together!).
How to Make Peanut Butter Chocolate Chip Bars
Step 1: Mix Dough
- Preheat oven to 350ºF.
- In a large mixing bowl, beat together unsalted butter (½ cup, i.e. 1 stick), light brown sugar (¾ cup), and granulated sugar (¼ cup) on medium speed for 30-60 seconds, or until combined. Mix in creamy peanut butter (¾ cup).
- Stir in the 1 whole egg, 1 extra egg yolk, and vanilla extract (1 teaspoon), followed by the baking soda (½ teaspoon) and salt (¼ teaspoon).
- Add all-purpose flour (1½ cups) and cornstarch (1 tablespoon) and mix until combined.
- Add semi-sweet chocolate chips (½ cup) and peanut butter chips (½ cup). Mix the dough until well combined.
Tip: This is a thick dough so it's best to use a stand mixer with the paddle attachment. But if you don't have one, simply use an electric hand mixer up until you're going to add the flour and oats, then mix by hand.
Step 2: Press into Pan & Bake
- Generously grease and line a light-colored metal 9×13 pan with parchment paper. Spread dough into an even layer in the pan. If desired, press a few extra chocolate chips on the top for added presentation.
- Bake for 14-16 minutes, or until edges are slightly golden brown. Do not overbake; it might look a little under-baked, but the residual heat from the pan will continue to bake the cookie even after you take it out of the oven.
Step 3: Cut into Squares
Cool completely before cutting - this is important! If you cut while they are warm, they will crumble. Store in an airtight container for 3-4 days or freeze up to 1 month.
Tips & Variations
- Switch up the chips: You can use anything like dark chocolate chips or chunks, milk chocolate chips, white chocolate chips, and butterscotch chips! You could even press pieces of a chocolate bar into the top of the bars.
- Add candy: These chewy peanut butter cookie bars would be so delicious with M&M's, Reeses Pieces, or chopped Reeses peanut butter cups.
- Turn into cookie cake: If you have a peanut butter lover in your life, this recipe is great for making peanut butter cookie cake!
Storage & Freezing
- Storage: Store in an airtight container for 3-4 days.
- Freeze: Freeze in an airtight container or freezer bag for up to 1 month. These cookie bars can dry out in the freezer so I recommend making them fresh for the best texture.
Looking for more easy peanut butter dessert recipes?
Love peanut butter desserts? Here are a few of my favorite recipes!
Peanut Butter Cookie Bars
Makes: 12
These soft & chewy peanut butter chocolate chip cookie bars are easy to make in a 9x13 pan! Add your favorite chocolate chips and mix-ins for the ultimate crowd pleaser!
Ingredients
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Instructions
- Preheat oven to 350ºF. While preheating, be sure to read tips & tricks in post above for recipe sucess.
- In a large mixing bowl, beat together ½ cup unsalted butter (i.e. 1 stick), ¾ cup light brown sugar, and ¼ cup granulated sugar on medium speed for 30-60 seconds, or until combined. Mix in ¾ cup creamy peanut butter.
- Stir in the 1 large egg, 1 egg yolk, and 1 teaspoon vanilla extract, followed by the ½ teaspoon baking soda and ¼ teaspoon salt.
- Add 1 ½ cups all-purpose flour and 1 tablespoon cornstarch and mix until combined.
- Add ½ cup semi-sweet chocolate chips and ½ cup peanut butter chips. Mix the dough until well-combined.
- Generously grease and line a light-colored metal 9x13 pan with parchment paper. Spread dough into an even layer in pan. If desired, press a few extra chocolate chips on the top for added presentation.
- Bake for 14-16 minutes, or until edges are slightly golden brown. Do not overbake; it might look a little under-baked, but the residual heat from the pan will continue to bake the cookie even after you take it out of the oven.
- Cool completely before cutting - this is important! If you cut while they are warm, they will crumble.
- Store in an airtight container for 3-4 days or freeze up to 1 month.
Notes from Melissa
Nutrition information is calculated using an ingredient database and should be considered an estimate. Based on 12 bars.