Tessa’s Recipe Rundown
TASTE: Peanut butter heaven! Peanut butter is added three ways in these bars for tons of delicious PB flavor.
TEXTURE: Thick and chewy, with a delightful crunch added thanks to all the mix-ins.
EASE: Practically effortless.
PROS: No chilling involved! They’re also easy to transport to your Christmas party.
CONS: None.
WOULD I MAKE THIS AGAIN? Yes!
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These Loaded Peanut Butter Christmas Cookie Bars will become your go-to bake this holiday season!
If you know me at all, you know I have a complete and total obsession with peanut butter.
When I decided to create a festive cookie bar this holiday season, I instantly knew that I wanted peanut butter to be involved.
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So I packed peanut butter into these Christmas bar cookies in three different forms!
These bars are loaded with peanut butter M&Ms, peanut butter chips, and an entire CUP of peanut butter. Plus, some chocolate chips.
I mean, you can’t go wrong with peanut butter and chocolate, right?
Adorably festive and ready in no time, these Peanut Butter Cookie Bars are sure to be the hit of your Christmas party, work potluck, or just a fun bake with the kids, ready to leave under the Christmas tree for Santa.
Sprinkle of Science
How to Make Loaded Peanut Butter Christmas Cookie Bars
What’s the Best Peanut Butter to Use for Peanut Butter Cookie Bars?
- I recommend using conventional peanut butter (Skippy / Jif) in these bar cookies.
- If using natural peanut butter, make sure it’s VERY well stirred to be completely smooth and cohesive, with no oily or dry bits.
- Natural peanut butter will yield a bolder peanut butter flavor, but it must be totally smooth.
- More on alternative nut butters below.
Can I Use Almond Butter Instead?
We haven’t tested these Cookie Bars using almond butter, but a 1:1 ratio swap worked perfectly with my Peanut Butter Cookies, so feel free to experiment here! Substitute the peanut butter M&Ms and PB chips with almond M&Ms – or white chocolate chips, toffee bits, or butterscotch chips could be fun, too!
Where to Find Holiday Peanut Butter M&Ms?
I typically find Christmas and other holiday-themed M&Ms at Target and larger supermarkets, but you can also grab them online here.
Can I Change the Mix-ins for Peanut Butter Cookie Bars?
Yes! Feel free to swap out the chocolate chips, peanut butter M&Ms, and peanut butter chips for the same amount of:
- Milk or dark chocolate chips
- Chocolate chunks
- Reese’s Pieces (but note this will make your bar cookies look more fall-themed)
- Or any other holly jolly mix-ins you like!
Just remember that substitutions for peanut butter M&Ms and/or peanut butter chips may yield bars with a milder peanut butter taste.
How to Make Chewy Cookie Bars & Avoid Dry Bars
- Be sure to measure your flour correctly. I highly recommend weighing your ingredients, but the spoon and level method will work if you don’t have a digital scale. This ensures accurate measuring to avoid cakey, dense, or tough cookie bars.
- Don’t reduce the sugar. Sugar does so much beyond simply sweetening, such as bringing moisture and extra chewiness to the bake. Read more about sugar’s role in baking here.
- Don’t overbake. Bake your Cookie Bars until they’re just golden brown on top. Residual heat will continue to bake them through, even if they seem a little jiggly when you remove them from the oven. They will firm up as they cool. They can take a little longer to bake if your oven runs cool. Learn more about ovens here.
What Pan to Use for Loaded Peanut Butter Christmas Cookie Bars?
This recipe was written for a 9×13-inch light-colored metal pan. Avoid using a glass pan here as it can dry out the edges of your bars before the middle can bake through. Learn more about Glass vs. Metal Baking Pans here.
Can I Halve This Recipe?
Yes – cut all ingredients in half and use an 8×8-inch light-colored metal pan, shaving a few minutes off the bake time.
Can I Make This Recipe into Regular Cookies?
I have a recipe for that! Use my Giant Reese’s Pieces Chocolate Chip Cookies recipe and swap out the Reese’s Pieces for holiday-themed peanut butter M&Ms. We actually used that recipe as the base in our testing, making adjustments to the leaveners (and peanut butter!) to result in the perfect Loaded Cookie Bars.
How to Store Cookie Bars?
Store Cookie Bars in an airtight container at room temperature for up to 5 days. Keep a tortilla in the container to keep them soft and chewy and prevent them from drying out as quickly.
Can You Freeze Loaded Peanut Butter Christmas Cookie Bars?
Yes! Wrap the whole slab or individual slices of bar cookies in plastic wrap and store inside an airtight container or freezer bag for up to 1 month. Thaw at room temperature for a few hours before serving.
More Christmas Recipes You’ll Love:
Loaded Peanut Butter Christmas Cookie Bars
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Ingredients
- 2 ½ cups (286 grams) all-purpose flour,
measured correctly - 1 teaspoon baking powder
- ¼ teaspoon baking soda
- ¾ teaspoon fine sea salt
- 1 stick (113 grams) unsalted butter, at cool room temperature
- 1 cup (270 grams) creamy peanut butter
- 1 cup (200 grams) packed light brown sugar
- 3/4 cup (150 grams) granulated sugar
- 2 large eggs, at room temperature
- 1 ½ tablespoons vanilla extract
- 1 tablespoon milk
- 1 cup (170 grams) peanut butter chips
- 1 cup (185 grams)
holiday Peanut Butter M&Ms + heavy ⅓ cup (70 grams), to decorate - 1 cup (170 grams) semisweet chocolate chips + ⅛ cup (21 grams), to decorate
- Flaky sea salt, for topping, optional
Instructions
- Preheat the oven to 350°F. Line a 9×13 metal baking pan with aluminum foil, using metal binder clips to keep foil in place. Spray sides and bottom of pan generously with cooking spray. Set aside.
- In a medium bowl, combine the flour, baking powder, baking soda, and salt. Set aside.
- In the bowl of an electric mixer fitted with the paddle attachment, beat the butter, peanut butter, brown sugar, and granulated sugar on medium-high speed until very well combined, about 2 minutes. Scrape down the sides and bottom of the bowl. Add the eggs, vanilla, and milk and beat until combined.
- On low speed, gradually add the flour mixture and beat until just combined. Dough will be thick. Add the peanut butter chips, M&Ms, and chocolate chips and mix until just combined. You may need to do this by hand with a spatula if your mixer isn’t strong enough.
- Remove the dough to the prepared pan, pressing into the pan evenly. Sprinkle with the reserved M&Ms and chocolate chips. Bake for about 30 minutes, or until the center is golden brown and just slightly jiggly. Sprinkle with flaky sea salt. Place pan on a wire rack and let cool completely before cutting into squares and serving.
- Store bars in an airtight container at room temperature for up to 5 days.
Recipe Notes
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Photos by Joanie Simon.
These bars are delicious and easy to make. Very peanut butter-forward, obviously, but everyone I’ve shared them with has greatly enjoyed them.
I converted these to Gf using Katarina Cermelj’s rules. They turned out great!
So happy you loved them, Bonnie! For other readers who may need to bake gluten-free, can you share what tweaks you made? Thanks in advance!
I reduced the butter by 30%, added 1/2 plus 1/8 tsp xanthan gum, and used her blend of 50% tapioca flour, 25% millet flour and 25% buckwheat flour. Because I am at high altitude I also increased the milk by 2 tsp.
I don’t have an electric mixer. Should I skip making this recipe?
Hi Tara! Unfortunately, this recipe requires the creaming method, which is very difficult to replicate without the use of an electric mixer. We have quite a few recipes that don’t need an electric mixer – maybe give Tessa’s Best Ever Chewy Brownies or Peanut Butter Chocolate Chip Cookies a try instead! Happy baking 🙂
Cook time the same for glass baking dish?
Hi Jess! We actually do not recommend using a glass pan for these bars. Tessa talks about why this is important in the pink tip box (above the recipe), along with loads of other great tips. Let us know what you think of these cookie bars once you give it a try! 🙂