CHEWY Monster Cookie Bars (with VIDEO)

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My Ultimate Monster Cookies are one of my favorite recipes on this site! The base recipe is so great because they have such a wonderful texture and these Monster Cookie Bars are just as delicious! They are thick and chewy and very simple to make since you can mix them by hand in one bowl, which means they are so quick and EASY! These bars are heavy on the peanut butter with extra soft and chewy texture, some bite from rolled oats and plenty of chocolate.

stack of monster cookie bars on parchment paper

WHY THIS RECIPE WORKS

Easy one bowl recipe - these monster cookie bars are so easy to whip up in one bowl with a simple whisk by hand. There's no mixer required and you get the delicious taste of Monster Cookies all in one pan.
Chewy oatmeal cookie bars - they have a wonderful chewy texture thanks to oats, honey and brown sugar.
Peanut butter cookie bars - monster cookies are basically oatmeal cookies with peanut butter and chocolate candy pieces so these bars have those same ingredients!
Dark chocolate chips - I love to add a mix of chocolate chips for different textures and a more interesting appearance. I use regular and mini dark chocolate chips.
Honey and sea salt - honey makes these bars extra chewy and flaky sea salt takes them over the top for the ultimate sweet & salty treat!

monster cookie bars sliced on parchment paper on cutting board

Unsalted butter - this recipe uses melted butter so there's no need to plan ahead to bring it to room temperature. It's part of what makes this recipe so easy!
Brown sugar - the molasses in brown sugar gives these bars a toffee-like flavor.
Peanut butter - this recipe works best with smooth or creamy peanut butter. If you only have chunky peanut butter, I would suggest adding a tablespoon or two more. It also can work with natural peanut butter, but the bars will be a bit more crumbly.

monster cookie bars lined up showing cross section

Honey - honey is a liquid sugar which helps to keep these bars chewy. It adds a wonderful floral sweetness that pairs well with peanut butter and gives the surface a golden brown color.
Rolled oats - this recipe is designed to use regular large flake old fashioned rolled oats. If you use quick oats or minute oats, then they will absorb more moisture and the bars will be too dry.
Dark chocolate chips - I use 70% chocolate chips for a rich chocolate taste to complement the sweetness. You can use any kind you like.
Candy-coated chocolate pieces - you can't have Monster Cookie Bars without candy coated pieces! Well actually you can... haha. You can just replace them with more chocolate chips but it won't look as fun!

STEP BY STEP INSTRUCTIONS

STEP 1). Combine wet ingredients. Mix together melted butter, peanut butter, brown sugar, granulated sugar, honey, egg and vanilla until smooth and glossy.
STEP 2). Mix in dry ingredients. Whisk in baking soda and salt. Then fold in the flour and oats.
STEP 3). Add chocolate chips and candies. Add the chocolate chips and candy-coated pieces and fold them through.
STEP 4). Spread out the batter. Press the batter into the prepared pan and top with extra chocolate chips and candies.
STEP 5). BAKE. Bake for 20-25 minutes until evenly golden and then sprinkle with sea salt while still warm. Let them cool completely before slicing.

monster cookie bars in baking pan fresh from the oven

monster cookie bars sliced on parchment paper with scoop of peanut butter

EXPERT BAKING TIPS

Measure the flour accurately to ensure you get the right texture. Too much flour will make these bars dry and crumbly instead of chewy, and too little will mean they will sink or collapse on cooling.
Do not over-bake these bars. They will be nicely golden brown but still a bit soft in the middle when they are ready.
Sprinkle the sea salt on top of the chocolate chips while they are still warm and melty if you like salty/sweet treats like I do.
Let the bars cool completely before slicing to ensure you get nice neat slices.

monster cookie bars slices piled onto each other on parchment paper on cutting board

RECIPE FAQ

How to make chewy monster cookie bars?

These bars stay chewy with a tablespoon of honey. Honey is a "humectant" and that's a technical term for compounds or ingredients that hold onto water very tightly. This prevents excessive moisture loss from the bars so that the moisture stays IN the cookie.

Can I add nuts to this monster cookie bars recipe?

Yes! You can add ½ cup of chopped almonds, walnuts or pecans. Peanuts would also be delicious!

Can I use quick oats to make monster cookie bars?

This recipe for calls for rolled oats which provide wonderful texture and the right amount of absorption in this cookie dough. You can use quick oats, however they will absorb more moisture and the bars will be slightly thicker and a bit more crumbly.

How do I store monster cookie bars?

These bars are best stored at room temperature in an airtight container for up to a week.

Can I freeze Monster cookies?

Yes, just place the cooled bars in a resealable freezer bag and freeze for up to 3 months. They just about 20 minutes to thaw.

Can these bars be made gluten-free?

Yes! You can make these bars with a 1:1 gluten-free flour blend and gluten-free oats. Actually, oats are naturally gluten-free (they do not contain gluten proteins), however they are often planted either in the same crop or nearby wheat crops so they can potentially be cross-contaminated with wheat.

Can these bars be made dairy-free?

Yes! I have also made these bars with coconut oil and they turned out wonderfully. Just replace butter with an equal amount of coconut oil.

If you love cookies, check out these recipes!

Chewy Pumpkin Chocolate Chip Cookies The BEST Chewy Pumpkin Cookies Chewy Brown Butter Snickerdoodles Cookies Brown Butter M&M Cookies Recipe Lemon Blueberry Cookies with White Chocolate Chunks Coffee Pecan Chocolate Chip Cookies Double Peanut Butter Chocolate Chunk Cookies Hazelnut Double Chocolate Chunk Cookies THE BEST Chewy Chocolate Chip Cookies – Bakery Style!

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