Peanut butter cookie bars – Easily turn chewy chocolate chip cookies into cookie bars and load them up with Reese’s Pieces for a mindblowing dessert.

Peanut Butter Cookie Bars

There are times when I agonize over what to bake. I’m a terrible decision-maker; too many choices destroy my ability to swiftly decide.

It’s probably the reason why I cut my to-make lists down a few weeks back to a much more manageable size, deleting things I was no longer interested in, that no longer got me excited. These peanut butter cookie bars, however, never left the list. They have remained an incredible dessert bar I’ve been meaning to share with you for what seems like ages (really, just since July though) and I finally remade them this weekend as a treat for our spooky night at the drive-in.

And truthfully, there are a couple of reasons why I chose these bars for our movie night: 1) We don’t go to movies without Reese’s Pieces and 2) aren’t these cookie bars just the perfect Halloween dessert??

Peanut Butter Cookie Bars

We actually don’t take road trips without Reese’s Pieces either (not even kidding) which is why the first time I made these bars was back in July for a special boat trip in Maine with my friends, Lydia and Annie.

These cookie bars were such a major hit that night in July that I was strongly urged to share them here.

The funny thing about them is that while they taste like the most amazing peanut butter cookie bars you might ever eat, there’s no actual peanut butter in them. Well, no actual scoop-from-the-jar peanut butter anyway. All of the flavor comes from those magical Reese’s Pieces.

Peanut Butter Cookie Bars

In any event, they’re a cinch to pull together with one bowl and a wooden spoon like I did in our rental house kitchen a few months ago. You’ll plop the dough into a baking pan and bake for 35 to 40 minutes. There’s nothing fussy about them and I suspect they’ll remain a family favorite of our for ages.

Peanut Butter Cookie Bars

Peanut Butter Cookie Bars

Peanut Butter Chocolate Chip Cookie Bars

Yield: 12-16 servings
Prep Time: 15 minutes
Cook Time: 40 minutes
Total Time: 55 minutes


  • 12 tbsp (1½ sticks) unsalted butter, melted and cooled until warm
  • 1 cup (9 oz) light brown sugar, packed
  • ½ cup (5 oz) granulated sugar
  • 1 large egg plus 1 egg yolk
  • 2 tsp pure vanilla extract
  • 2 cups plus 2 tbsp (10 5/8 oz) all-purpose flour
  • ½ tsp baking soda
  • ½ tsp table salt
  • 1 cup Reese's Pieces candies, plus extra for "garnish"
  • ½ cup semisweet chocolate chips


  1. Preheat oven to 325° F.
  2. Using a wooden spoon and in a large bowl, beat the melted butter with the sugar until the butter is incorporated. Mix in the egg, yolk, and vanilla until well-combined. Measure the flour, baking soda, and salt into the bowl and stir until just combined and only just a few flour streaks barely remain - the dough should look a little dry. Fold in the Reese's Pieces and chocolate chips until they are just incorporated - do not over mix as this will cause the bars to deflate in the center of the pan. Dump the dough into an 8x8-inch or a 9x9-inch baking pan and spread it out with your fingers. Don't press the dough down, just roughly set it in the pan. Toss a few more Reese's Pieces over the top of the dough before baking.
  3. Bake for 35 to 40 minutes, rotating the pan halfway through the time. Darker pans will need closer to 35 minutes so watch them carefully. The bars will be done when the center no longer jiggles when the pan is gently shaken. Allow the bars to cool completely in the pan on a wire rack before cutting and serving. Bars will keep for 2-3 days in an airtight container at room temperature.


adapted from these chocolate chip toffee bars

Recommended Products

As a member of the Amazon Associate affiliate program, I earn a small percentage from your qualifying Amazon purchases when you click the Amazon links on this page. I'm not informed of who purchases what, just of what products are purchased.

How much do you love this recipe?

Follow Smells Like Home on Pinterest and click that little Pin button at the top of this recipe card to save this recipe and share with your Pinterest followers!

You Might Also Like:

Leave a Comment

  • Sarah
    October 26, 2015 at 6:15 PM

    These look INCREDIBLE. Yum!

  • Kayle (The Cooking Actress)
    October 26, 2015 at 7:51 PM

    uh yeah these are PERFECT-so simple and peanut buttery and delicious!

  • David
    December 12, 2020 at 2:07 PM

    These were super easy to make and didn’t create a big mess to clean up after either, plus they were delicious. I couldn’t find any Reese’s pieces (though I’m sure if I tried harder I could locate some here in the UK) so I threw some peanut butter in, and some marshmellows and some darkchocolate and then again on the top before they went in the oven. Cheap to make too.

    – Easy to make
    – Not a huge mess to clean up after
    – Doesn’t require loads of kitchen equipment you don’t have
    – Cheap ingredients
    – Delicious treat
    – Eating so much sugar is bad

    • Tara
      December 28, 2020 at 9:18 AM

      Thanks so much for coming back to leave a review, David! So glad you loved these bars! Adding marshmallows sounds brilliant too! If you can find peanut butter chips (like chocolate chips, but peanut butter flavored), they will work too.