My Ultimate Monster Cookies are one of my favourite 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. So quick and EASY!
WHY YOU WILL LOVE THIS RECIPE
- 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!
INGREDIENTS FOR MONSTER COOKIE BARS
This recipe comes together with just simple pantry ingredients!
- 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 flavour.
- 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.
- Honey - honey is a liquid sugar which helps to keep these bars chewy. It adds a wonderful floral sweentness that pairs well with peanut butter and gives the surface a golden brown colour.
- 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. Whisk 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 22-25 minutes until evenly golden and then sprinkle with sea salt while still warm. Let them cool completely before slicing.
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.
- Do not over-bake these bars. They will be nicely golden brown but still 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 so that they stick.
- Let the bars cool completely before slicing to ensure you get nice neat slices.
What type of oats should I use in Monster Cookie Bars?
I use regular large flake old fashioned rolled oats to make these monster cookie bars. I would not recommend making them with quick oats because they will be too dry and crumbly.
What is a substitute for honey?
You can use agave syrup, corn syrup or golden syrup in place of honey. I would not recommend maple syrup since it has a higher moisture content and the bars might not be as chewy. It will still work though. If you want extra rich bars, you can use "fancy" or "light" molasses.
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.
How do I store chewy Monster Cookie Bars?
These bars are best stored at room temperature in an airtight container for up to 5 days.
Can I freeze these bars?
Yes! If you would like to freeze them, I would suggest slicing them first and then freezing individually on a parchment-lined tray before storing in a zip-top freezer bag for up to 3 months.
If you love oats, check out these recipes:Chewy Oatmeal Chocolate Chip CookiesGooey Almond Oatmeal Chocolate Chip Cookie Bars (gf, df option)Chewy Reese’s Peanut Butter White Chocolate Chunk Oatmeal CookiesUltimate Monster CookiesThick White Chocolate Chunk Peanut Butter Oatmeal Raisin CookiesDark Chocolate Cherry Coffee Oatmeal Cookies
Chewy Monster Cookie Bars
- ½ cup 120ml smooth peanut butter
- ¼ cup 56g unsalted butter melted
- ½ cup 110g packed light brown sugar
- ¼ cup 50g granulated sugar
- 1 tablespoon 15ml honey
- 1 large egg at room temperature
- 1 teaspoon 5ml pure vanilla extract
- ¼ teaspoon baking soda
- ¼ teaspoon salt
- ¾ cup 105g all purpose flour
- ¾ cup 75g old fashioned rolled oats
- ⅔ cup 100g dark chocolate chips plus more for sprinkling on top
- ⅓ cup 70g candy coated chocolates plus more for sprinkling on top
- flaky sea salt for sprinkling
- Preheat the oven to 350 degrees F and line an 8×8 square baking pan with parchment paper. Let the paper to hang over the sides about 2 inches for easy removal.
- Combine melted butter, peanut butter, brown sugar, granulated sugar, honey, egg, and vanilla in a large bowl and whisk until well combined, smooth and glossy.
- Add baking soda and salt and whisk to combine. Add the flour and oats and fold it in with a spatula. Before it is completely blended, add the chocolate chips and chocolate candy pieces and fold them through.
- Press the dough into the lined baking pan and scatter a few extra chocolate chips and candies on top.
- Bake for 22-25 minutes until evenly golden brown. Sprinkle with flaky sea salt and let cool completely before slicing, then enjoy!