Triple Peanut Butter Monster Cookie Bars

I make my fair share of treats, and have the hodgepodge of random add-ins in my pantry to show for it.

Half-used bags of chocolate chips, peanut butter chips, and a random assortment of candy were taking over the cupboard so I found a home for them.

In these bars.

They’re the perfect bar to toss in everything but the kitchen sink.

Use this flexible and forgiving dough base as your opportunity to stir almost anything that’s plaguing your pantry into it.

What else are you going to do with 1/3 cup chocolate-covered sunflower seeds from your last Trader Joe’s impulse buy or that small handful of butterscotch chips from your last batch of cookies, or a few stray marshmallows.

Use up last year’s Halloween candy or Easter candy. Those Fun-Size Twix bars are begging to be diced and tossed in. Don’t pretend you don’t discover random candy from months ago. Well, I do. Life of a food blogger.

The bars come together in 5 minutes in one bowl, no mixer needed. Unlike making cookies, there’s no dough to chill, and they’re ready in under 30 minutes from start to finish.

I used my go-to blondie base, with a half-cup peanut butter stirred in, before stirring in the kitchen sink.

I had partially used bags of Peanut Butter M&M’s, peanut butter chips, chocolate chips, chocolate chunks, toffee bits, and included them all.

Because peanut butter is used three times – peanut butter that’s stirred into the dough, Peanut Butter M&Ms, and peanut butter chips – they pack a bold, peanut buttery punch.

They’re very moist and soft. The edges turn slightly chewy, while the interior remains a squishy, soft heaven.

The crunchy candy coating of the M&Ms and their firmness, coupled with Heath toffee bits, are the perfect texture contrast to the buttery, peanut buttery, dense, melt-in-your mouth dough.

There’s plenty of chocolate, too. Chocolate and peanut butter just go together. The abundance of melted chocolate chips is practically mandatory with all that peanut butter.

Soft, chewy, fast, easy, peanut butter used three times, and you can clean out your cupboards. That’s success.

And let’s face it, any time you can bake candy into a dessert, you won’t hear too many complaints.

Cleaning out your pantry never tasted so good.

Yield: 12 generous squares

Triple Peanut Butter Monster Cookie Bars

Prep Time 5 minutes
Cook Time 25 minutes
Total Time 30 minutes

Peanut butter is used three times in these dense, rich, moist, fast, and easy bars. There’s peanut butter stirred into the dough, Peanut Butter M&Ms, and peanut butter chips, so the bars pack a bold, peanut buttery punch. There’s plenty of chocolate, the perfect compliment to all that peanut butter. Use the dough base as a blank canvas and start cleaning out your pantry – butterscotch or white chocolate chips, nuts and seeds, dice old holiday candy and toss it in. Mix and match with the add-ins you have on hand rather than buying new. Cleaning out your pantry never tasted so good.


  • 1/2 cup unsalted butter (1 stick), melted
  • 1 large egg
  • 1 cup light brown sugar, packed
  • 1 tablespoon vanilla extract
  • heaping 1/2 cup creamy peanut butter (use Jif, Skippy, etc.; don’t use homemade or natural – too runny)
  • 1 cup all-purpose flour
  • 1 cup Peanut Butter M&Ms
  • 3/4 cup semi-sweet chocolate chips or chunks, or a combination
  • 1/2 cup Reese’s Peanut Butter Chips
  • 1/3 cup Heath Bar Toffee Bits


  1. Preheat oven to 350F. Line an 8-by-8-inch baking pan with aluminum foil, spray with cooking spray; set aside.
  2. In a large, microwave-safe bowl melt the butter, about 1 minute on high power.
  3. Wait momentarily before adding the egg so you don’t scramble it. Add the egg, brown sugar, vanilla, and whisk until smooth.
  4. Add the peanut butter and whisk or stir until smooth and incorporated.
  5. Add the flour and stir until just combined, don’t overmix.
  6. Add all remaining add-ins and fold to incorporate.
  7. Turn batter out into prepared pan, smoothing the top lightly with a spatula. I like to strategically place a few M&Ms on the top of the batter for a nice visual effect.
  8. Bake for about 25 minutes, or until top is set. A toothpick inserted in the center should come out clean, or with a few moist crumbs, but no batter. Allow bars to cool in pan for at least 30 minutes before slicing and serving. Bars will keep airtight at room temperature for up to 1 week, or in the freezer for up to 6 months.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 522Total Fat: 39gSaturated Fat: 20gTrans Fat: 1gUnsaturated Fat: 16gCholesterol: 83mgSodium: 245mgCarbohydrates: 39gFiber: 2gSugar: 26gProtein: 7g

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What’s the last pantry cleanout recipe you’ve made? What do you put in your Monster Bars?