Your weekend lineup needs these salted brown butter peanut butter M&M cookie bars.
These bars are gooey and chewy, with deeply flavored brown butter and pockets of melty peanut butter M&Ms. They’re indulgent, easy to make, and perfect for sharing — or keeping all to yourself.
Start with perfectly browned butter. The nutty, caramel notes of the butter elevate a simple cookie bar into something special — rich, golden, and irresistible.
Quick confession: peanut butter M&Ms are my favorite. Their creamy centers paired with crisp candy shells make them ideal for baking. The Easter pastel varieties are especially fun — slightly larger and brighter, they add both flavor and a colorful, speckled appearance to the finished bars.
They also look beautiful — soft golden cookie bars dotted with colorful peanut butter candies and finished with a sprinkle of flaky salt. The visual pop makes them perfect for parties, gifts, or an elevated weeknight dessert.
Why these bars work
The recipe is based on a tried-and-true brown butter cookie bar base that yields consistently tender, chewy bars. The brown butter brings depth and a caramel-like quality, while the peanut butter M&Ms add melty centers and satisfying crunch. A final pinch of flaky salt balances the sweetness and highlights the nutty flavors.
These bars are very forgiving. Once you’ve browned the butter, the recipe comes together in one bowl: brown sugar whisked with the warm butter, eggs stirred in, dry ingredients folded in, then the peanut butter M&Ms. Press the dough into a prepared pan, bake until golden and set, and finish with maldon or flaky salt.
Make them ahead for easy entertaining — they keep well and transport beautifully. Warm from the oven, they’re irresistible with a scoop of vanilla ice cream for an extra-special treat.
Peanut Butter Cookie Bars
Salted Brown Butter Peanut Butter M&M Cookie Bars
12
people
20 mins
30 mins
50 mins
Ingredients
- 1 cup unsalted butter
- 1 1/2 cups light brown sugar, loosely packed
- 2 eggs, lightly beaten
- 1 tablespoon vanilla extract
- 2 cups all-purpose flour
- ½ teaspoon baking soda
- ½ teaspoon salt
- (9 ounce) bag peanut butter M&Ms
- Maldon or flaky sea salt, for topping
Instructions
-
Preheat the oven to 350°F and have a 9×13-inch baking dish ready.
-
Whisk together the flour, baking soda, and salt in a small bowl and set aside.
-
Melt the butter in a skillet over medium heat. Let it simmer and stir occasionally until brown bits form and the butter smells nutty and caramelized. Remove from heat and stir for about 30 seconds. Let the brown butter cool slightly, then brush a little of it over the bottom and sides of the prepared dish.
-
Place the brown sugar in a large bowl. Pour in the warm brown butter and mix until smooth; the sugar will begin to dissolve. Add the eggs one at a time, stirring after each addition, then stir in the vanilla.
-
Use a wooden spoon to stir in the dry ingredients until almost combined. Fold in the peanut butter M&Ms so they’re evenly dispersed.
-
Press the mixture into the buttered 9×13 dish and bake 25 to 30 minutes, until the top is golden and the center is set. Remove from the oven and immediately sprinkle generously with flaky salt. Cool completely before slicing into bars.
Did you make this recipe?
Tag your photos with #howsweeteats and share your results — it’s always a joy to see how these bars turn out for you.
These are the chewiest, most satisfying cookie bars — salty, peanut-buttery, and perfect for every occasion.