Monster Cookie Bars
- By Amy Dong
- Updated Dec. 19, 2024
These Monster Cookie Bars are thick, chewy, and supremely satisfying – just like the classic cookies, but even easier to make. They’re chock full of your favorite goodies and a guaranteed crowd favorite.
In This Article
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Why This Recipe Stands Out
We all love a good Monster Cookie Recipe, and this recipe for Monster Cookie Bars are a guaranteed hit. Here’s why we’re obsessed:
- Chewy Texture: The combination of oats and peanut butter gives these bars an incredibly satisfying chew, just like these Peanut Butter Oatmeal Cookies.
- Easy to Make: Like with our Carmelita Bars, there’s no need to scoop and bake individual cookies. This makes it easy to get a whole batch of bars into the oven in no time.
- Perfect for Parties: Put a plate of these delicious bars out on the dessert table and watch them vanish right before your eyes. People absolutely adore these chewy bars.
- Make-Ahead: The flavor of these bars actually gets better over time, so they’re a great make-ahead option for your next get-together, like this incredible Key Lime Pie.
- Freezer-Friendly: The baked bars can be wrapped tightly and frozen for up to 2 weeks.
- Gluten Free: Because we don’t use flour in this recipe, it’s naturally gluten free. If needed, check that your oats and other ingredients are certified as such.
Key Recipe Ingredients
- Peanut Butter – Using creamy peanut butter is crucial in this recipe, as it not only adds a rich, nutty flavor but also keeps the bars moist and chewy. Buy pre-stirred peanut butter that has no oil separation.
- Quick-Cooking Oats – Quick oats add a chewy texture and a hint of nutty flavor that complements the peanut butter and chocolate.
- Eggs – The eggs in this recipe act as a binding agent, helping to hold the bars together and giving them a soft, tender texture.
- Brown Sugar – The brown sugar adds sweetness and also contributes to the chewy texture of the bars.
- Chocolate Chips and M&M’s – These add-ins not only make the bars look colorful and fun but also add pockets of melty chocolate and a crunchy candy shell.
Substitutions And Variations
Here are some of our favorite variation and substitution ideas:
- Peanut Butter: If you prefer a different type of nut or seed butter, feel free to substitute the peanut butter with almond butter, cashew butter, or sunflower seed butter.
- Oats: If you’d like a more hearty texture, you can use old fashioned rolled oats or a mixture of rolled oats with quick oats.
- Chocolate Chips: This recipe calls for semi-sweet chocolate chips, but you can use milk chocolate chips, dark chocolate chips, white chocolate chips, peanut butter chips, or any combination.
- Mix-ins: The M&M’s can be substituted with your favorite candy or chocolate chunks. Try using Reese’s Pieces, chopped Snickers, or Twix.
Step-By-Step Recipe Instructions
- Preheat oven to 350F and lightly grease a 9×13″ baking pan.
- In a stand mixer, combine sugars and eggs on medium speed until well combined.
- Add cinnamon, salt, vanilla, peanut butter, and butter; mix well until fully incorporated.
- Stir in chocolate chips, baking soda, and oats. Press the dough into the prepared pan. Evenly press M&M’s on top.
- Bake for 20 minutes or just until the sides are golden brown.
- Cool in the pan on a wire rack. Once completely cooled, cover and chill. Cut into squares and serve.
For full list of ingredients and instructions, see recipe card below.
How To Prep Ahead
Take a look at our favorite prep-ahead strategies for this recipe:
- Chill the Dough: You can make the dough according to the recipe and chill it for up to 2 days before baking. Make sure to allow the dough to reach room temperature before popping it in the oven.
- Make and Freeze: These bars can also be baked and then frozen for up to 2 weeks. This is a great option if you want to get a head start on your baking or if you want to make a big batch to enjoy later.
Commonly Asked Questions
What kind of oats should I use for this monster cookie bars recipe?
We recommend using quick-cooking oats for this recipe. They blend well with the other ingredients and give the bars a nice texture.
Why do I need to chill the bars before cutting them?
Chilling the bars helps them set firmly, making it easier to cut them into neat squares. It also enhances the flavor and texture, giving you the perfect monster cookie bars.
What if my bars came out too hard
If your bars turned out too hard, most likely, they were over-baked. Make sure to take them out of the oven as soon as the sides are golden brown. Remember, the bars will continue to set firmly upon cooling.
How long do monster cookie bars keep?
These bars can be kept in an airtight container at room temperature for up to 1 week. You can also freeze them for 2 weeks.
Did you make this?
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Monster Cookie Bars
These Monster Cookie Bars will only dirty one bowl, and super delicious! They're thick, chewy, satisfying, and wonderfully chocolatey.
Ingredients
- ½ cup granulated sugar
- ⅔ cups light brown sugar, tightly packed
- 2 large eggs, room temp
- 2 tsp ground cinnamon
- ¼ tsp table salt
- 1 tsp pure vanilla extract
- 1 cup creamy peanut butter
- ⅓ cup salted butter, softened to room temp
- 1 ½ cup semi-sweet chocolate chips
- 1 tsp baking soda
- 3 cups quick-cooking oats
- ⅔ cup M&M’s
Instructions
- Preheat oven to 350F with rack on lower middle position. Lightly grease a 9×13″ glass baking pan; set aside.
- In the bowl of a stand mixer fitted with paddle attachment, mix together both sugars and eggs on medium speed, until well combined.
- Add cinnamon, salt, vanilla, peanut butter, and butter; mix until fully incorporated.
- Stir in the chocolate chips, baking soda, and oats to combine well. Scrape dough into prepared pan and lightly/evenly press to fill all corners. Lightly press M&M's evenly across top of dough.
- Bake 20 minutes or just until sides are golden brown. Do not over-bake. Bars will continue to set firmly upon cooling.
- Cool in pan, on wire rack completely. Cover and chill for ease of cutting. Cut chilled bars into squares and serve.
Notes
- Make sure your eggs are at room temperature. This will help them mix more easily into the dough and will also help your cookie bars to rise properly.
- When measuring your brown sugar, very tightly pack it into the measuring cup.
- Buy pre-stirred creamy peanut butter that has no oil separation. It blends more easily into the dough and gives your bars a smooth, consistent texture.
- Baked bars can be wrapped tightly and frozen for up to 2 weeks.
- For fun variations and substitutions, see original article.
- This recipe is part of our Delicious Dessert Bars Collection.
Nutrition (per serving)
Calories: 341kcal | Carbohydrates: 38g | Protein: 7g | Fat: 19g | Saturated Fat: 8g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 7g | Trans Fat: 0.2g | Cholesterol: 27mg | Sodium: 179mg | Potassium: 235mg | Fiber: 3g | Sugar: 25g | Vitamin A: 143IU | Vitamin C: 0.05mg | Calcium: 43mg | Iron: 2mg
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