Peanut Butter Cookie Bars Recipe

Few things evoke the warm nostalgia of homemade baking quite like peanut butter cookies. Their irresistible aroma wafting through the kitchen, the perfect balance of salty and sweet, and the soft, chewy texture that melts in your mouth—these cookies are a beloved classic across generations. But what if you could enjoy all that peanut butter cookie goodness in a format that’s easier to slice, share, and savor? Enter the Peanut Butter Cookie Bars—a delightful twist on a timeless treat that combines the best of both worlds: the classic flavor of peanut butter cookies with the convenience and rustic charm of a bar cookie.

Peanut butter bars bring a new dimension to the familiar cookie experience. Instead of shaping and scooping individual cookies, you simply spread the batter into a pan and bake it all at once. This method not only saves time and effort but also yields a batch of soft, chewy bars with edges that are slightly crisp and interiors that stay perfectly tender. It’s a texture and flavor contrast that keeps every bite interesting, whether you’re enjoying a quick snack, a lunchbox treat, or an after-dinner dessert.

What makes these bars truly special is their versatility. You can customize them with classic add-ins like chocolate chips, chopped peanuts, or even swirls of melted chocolate or caramel for an indulgent finish. They can be made with creamy or chunky peanut butter, depending on whether you prefer a smooth, velvety texture or a bit of satisfying crunch. And because they’re baked in a single pan, they’re perfect for feeding a crowd or packaging up as thoughtful homemade gifts.

Beyond their deliciousness, peanut butter cookie bars also bring a comforting sense of home. They’re a go-to recipe for beginner bakers who want to try their hand at something easy yet impressive. They’re a crowd-pleaser at potlucks, bake sales, and family gatherings. And they’re the kind of treat that feels just as right at a casual picnic as they do alongside a steaming cup of coffee or a cold glass of milk.

Step-by-Step Instructions: Peanut Butter Cookie Bars

Making peanut butter cookie bars is wonderfully straightforward, but the magic lies in attention to detail and following each step carefully to achieve that perfect chewy texture and rich peanut butter flavor.

Step 1: Gather and Measure Your Ingredients Accurately

Baking is a science, so precise measurement is key.

• Use measuring cups and spoons for dry ingredients.

• Use a liquid measuring cup for any liquids.

• If possible, weigh ingredients for extra accuracy.

Typical ingredients include:

• Peanut butter (creamy or chunky)

• Unsalted butter, softened

• Granulated sugar

• Brown sugar (adds moisture and chewiness)

• Eggs (usually room temperature)

• Vanilla extract

• All-purpose flour

• Baking soda

• Salt

Step 2: Prepare Your Baking Pan

• Select an 8×8 or 9×13 inch baking pan, depending on how thick you want your bars.

• Lightly grease the pan with butter or non-stick spray.

• For easier removal, line the pan with parchment paper or aluminum foil, leaving an overhang on two sides to lift the bars out easily after baking.

Step 3: Cream the Butter and Sugars

• In a large mixing bowl, use an electric mixer (or stand mixer) to cream together softened butter, granulated sugar, and brown sugar.

• Beat on medium speed for 2–3 minutes until the mixture is light, fluffy, and pale in color.

• Proper creaming incorporates air, which helps the bars have a tender crumb.

Step 4: Add Peanut Butter, Eggs, and Vanilla

• Add the peanut butter to the creamed butter and sugar mixture.

• Beat on medium speed until well combined and smooth.

• Add eggs one at a time, beating well after each addition to incorporate fully.

• Stir in vanilla extract.

• At this stage, the batter should be thick, creamy, and homogenous.

Step 5: Combine Dry Ingredients Separately

• In a separate bowl, whisk together the all-purpose flour, baking soda, and salt.

• This ensures the baking soda is evenly distributed and prevents clumping.

• Sifting the flour is optional but helps create a lighter texture.

Step 6: Gradually Mix Dry Ingredients into Wet

• Slowly add the dry ingredients into the wet peanut butter mixture.

• Mix on low speed or fold with a spatula to avoid overmixing.

• Overmixing develops gluten, which can make bars tough rather than tender.

• Stop mixing once flour is just incorporated and no streaks remain.

Step 7: Optional Add-Ins and Mix-Ins

• At this point, fold in any optional extras such as:

  • Chocolate chips or chunks

  • Chopped peanuts for crunch

  • White chocolate chips

  • Toffee bits

  • Mini peanut butter cups, roughly chopped

• These add texture and bursts of complementary flavor.

Step 8: Transfer Batter to Prepared Pan and Spread Evenly

• Use a rubber spatula to scrape the batter into the prepared pan.

• Spread the batter evenly and gently press down to create a smooth, uniform surface.

• Don’t over-press, as you want to maintain some airiness in the batter.

Step 9: Bake at the Right Temperature

• Preheat your oven to 350°F (175°C).

• Bake the bars for 20–25 minutes if using an 8×8 pan; 25–30 minutes for a 9×13 pan.

• Baking time depends on thickness and oven variability.

• The bars are done when the edges turn golden brown and a toothpick inserted in the center comes out with a few moist crumbs (not wet batter).

Step 10: Cool Completely Before Cutting

• Allow the bars to cool fully in the pan on a wire rack.

• Cooling is crucial for the bars to set and firm up.

• If cut too soon, the bars can crumble or fall apart.

Step 11: Slice into Bars

• Use the parchment paper overhang to lift the bars from the pan.

• Place on a cutting board and use a sharp knife to cut into squares or rectangles.

• For clean cuts, wipe the knife between slices.

• Store the bars in an airtight container at room temperature or in the refrigerator for longer freshness.