The Ultimate Guide to Soft & Chewy Monster Cookies: Peanut Butter, Oatmeal & M&M Perfection

Prepare to be amazed by these truly ginormous, soft, and unbelievably chewy monster cookies! Bursting with the irresistible flavors of creamy peanut butter, hearty oatmeal, rich chocolate chips, and vibrant M&Ms, this recipe delivers a texture sensation unlike any other. Each bite offers a delightful medley of chewiness and crunch, making these cookies a favorite for both adults and children alike. Not only are they packed with an incredible depth of flavor, but they also bake up wonderfully thick, ensuring a substantial and satisfying treat.

This recipe was originally published previously and has been meticulously updated on November 3, 2022, to include brand-new, helpful photos, essential baking tips, and a slightly refined ingredient list to ensure the absolute best monster cookie experience possible.

What Makes Monster Cookies So Irresistible?

Monster cookies are a glorious culinary mash-up, bringing together the very best elements of several classic cookie varieties: the comforting chewiness of oatmeal cookies, the rich, nutty depth of peanut butter cookies, the fun crunch of M&M cookies, and the classic sweetness of chocolate chip cookies. The result is a uniquely flavorful and textural masterpiece. The harmonious blend of creamy peanut butter with the sweet chocolate creates a flavor profile that is simply divine. This particular recipe excels at producing cookies that are perfectly thick—robust enough to hold an abundance of chocolate chips and M&Ms—yet still maintain that coveted deliciously soft and chewy center.

One of the greatest advantages of this recipe is that there’s absolutely no need to chill the dough before baking. This means you can whip up a batch of these incredible cookies from start to finish without lengthy delays, making them perfect for those spontaneous baking cravings. However, for future convenience, you certainly have the option to prepare the dough balls in advance and freeze them for later enjoyment.

The Secret to Perfect Monster Cookies

At the heart of every great monster cookie are its four signature components: peanut butter, oats, M&Ms, and chocolate chips. Each ingredient plays a crucial role in creating the unique flavor and texture profile that defines these beloved treats. Understanding the nuances of each can elevate your baking from good to truly exceptional.

Essential Ingredients & Why They Matter

• Peanut Butter: For consistent results, it’s best to use commercially prepared, smooth peanut butter. Brands like Jif or Skippy work wonderfully. Natural peanut butters, where the oil often separates, can lead to varying oil content and inconsistent cookie texture. The peanut butter contributes not only its iconic nutty flavor but also to the cookie’s tender crumb and moistness.
• Oats: Old-fashioned oats, also known as large rolled oats, are highly recommended for this recipe. Their larger flakes provide a delightful chewiness and structure that quick oats simply cannot replicate. While quick oats will technically work, they tend to disappear more into the dough, yielding a less distinct texture. Avoid steel-cut or instant oats altogether, as their different cooking properties will not suit this cookie recipe.
• Chocolate Chips: You can use any variety you prefer—milk, semi-sweet, or dark chocolate chips. Mini chocolate chips or standard-sized chips will both melt beautifully and provide bursts of chocolatey goodness throughout the cookie. Feel free to mix and match for added complexity!
• M&Ms: These colorful candies add a playful crunch, extra chocolate flavor, and a vibrant visual appeal. Both regular and mini M&Ms work perfectly. Don’t hesitate to use seasonal M&Ms to customize your cookies for holidays or special occasions.
• Butter and Sugars: Softened unsalted butter, combined with both brown sugar and granulated sugar, forms the foundational fat and sweetness. The brown sugar contributes to the cookies’ chewiness and a hint of molasses flavor, while granulated sugar ensures crisp edges. Using equal amounts of butter and peanut butter strikes a perfect balance for soft, flavorful cookies.
• Egg and Vanilla Extract: A large room-temperature egg binds the ingredients and adds moisture, contributing to the cookies’ structure and richness. Vanilla extract enhances all the other flavors, giving the cookies a warm, inviting aroma.
• Flour and Leavening Agents: All-purpose flour provides the necessary structure. Baking soda and baking powder work together to give the cookies a lift and contribute to their soft, chewy texture. A touch of cornstarch (also known as cornflour in the UK and Australia) is often included to further tenderize the cookies and ensure they stay wonderfully soft.
• Salt: A small amount of salt is crucial for balancing the sweetness and enhancing the flavors of the other ingredients, especially the peanut butter and chocolate.

Step-by-Step Baking Instructions for Perfect Monster Cookies

Achieving bakery-quality monster cookies at home is simpler than you think. Follow these detailed steps and tips for perfectly thick, soft, and chewy cookies every single time. Even if you’re a seasoned baker, these pointers will help you master this delightful recipe.

1. Prepare Your Workspace and Oven: Begin by preheating your oven to 350°F (180°C). If you have a convection oven, set it to 325°F (170°C). This ensures your oven is at the correct temperature for even baking. Line two large baking sheets with parchment paper or silicone baking mats. This prevents sticking and makes cleanup a breeze.
2. Cream Butter, Sugars, and Peanut Butter: In a large mixing bowl, combine the softened unsalted butter, brown sugar, granulated sugar, and peanut butter. Beat these ingredients together with an electric mixer on medium speed until the mixture is light, fluffy, and well combined. The butter should be soft but not melted, allowing it to incorporate air effectively. This creaming process is vital for the cookies’ texture.
3. Add Egg and Vanilla: Next, beat in the large egg and vanilla extract. Ensure your egg is at room temperature; this helps it emulsify better with the butter mixture, leading to a smoother dough and a more uniform bake. Mix until just combined, being careful not to overmix.

   

4. Incorporate Dry Ingredients: Turn off your mixer. Add the all-purpose flour, cornstarch, baking powder, baking soda, and salt to the wet ingredients. Before turning on the mixer, give the dry ingredients a few gentle stirs by hand with a spatula. This prevents a “flour explosion” when you switch on the mixer. Then, beat on low speed until the dry ingredients are just incorporated into the dough. Overmixing flour can lead to tough cookies.
5. Stir in the Oats: Now, it’s time to add the old-fashioned rolled oats. Stir them into the dough until evenly distributed. As mentioned earlier, rolled oats are preferred for their superior texture and chewiness compared to quick oats.

   

6. Fold in Chocolate Chips and M&Ms: Finally, fold in the chocolate chips and M&Ms using a spatula. Make sure they are evenly distributed throughout the dough, so every cookie gets a generous share of these delicious mix-ins.
7. Portion the Dough: For perfectly sized “monster” cookies, use a 3-tablespoon cookie scoop (or two scoops from a 1.5-tablespoon scoop) to form dough balls. This ensures consistency in size and baking time. Using a scoop also helps keep your hands clean and prevents the dough from getting too sticky. Place the dough balls about 2-3 inches apart on your lined baking sheets to allow for spreading.

   

8. Bake to Golden Perfection: Bake one cookie sheet at a time in the preheated oven for approximately 11-13 minutes. The exact baking time may vary depending on your oven and the size of your cookies. Look for the tops to appear set and the edges to be lightly golden brown. The centers might still look slightly soft, which is perfect for a chewy texture.
9. Cool and Garnish (Optional): Once out of the oven, let the cookies cool on the baking sheet for at least 10 minutes. This allows them to set up and prevents them from falling apart when transferred. While the cookies are still warm, you can press a few extra chocolate chips and/or M&Ms onto their tops for a beautiful, bakery-style finish. After 10 minutes, carefully transfer the cookies to a wire rack to cool completely.

Pro Tip for Smaller Cookies: If you prefer smaller cookies, use approximately 1.5 tablespoons of dough per cookie. These will bake faster, typically needing only 8-10 minutes in the oven.

Tips for Achieving the Best Monster Cookies Every Time

• Room Temperature Ingredients: Ensure butter and eggs are at room temperature. This allows them to cream together more easily and uniformly, resulting in a smoother dough and better cookie texture.
• Don’t Overmix: Once you add the flour, mix only until just combined. Overmixing develops gluten, which can lead to tough cookies.
• Properly Measure Flour: Spoon and level your flour (don’t scoop directly from the bag) to avoid adding too much, which can make cookies dry and dense.
• Even Baking: Bake one tray at a time in the center of your oven for the most even heat distribution. If baking multiple trays, rotate them halfway through.
• Watch for Doneness: Cookies are done when the edges are set and lightly golden, and the centers still look slightly soft. They will continue to set as they cool.

Freezing Monster Cookie Dough for Later

Absolutely! Monster cookies are fantastic for meal prepping or simply having a stash of ready-to-bake treats. Preparing the dough in advance and freezing it is a convenient way to enjoy fresh-baked cookies whenever the craving strikes.

To freeze the dough:

1. Prepare the cookie dough as directed in the recipe up to the point of forming balls.
2. Form the dough into individual balls, using your cookie scoop, just as if you were going to bake them immediately.
3. Place the dough balls on a baking sheet lined with parchment paper, ensuring they don’t touch.
4. Freeze the dough balls on the baking sheet for about 1-2 hours, or until they are firm. This step prevents them from sticking together in the freezer bag.
5. Once frozen solid, transfer the dough balls to a freezer-safe bag or an airtight container. Remove as much excess air as possible to prevent freezer burn.
6. Store in the freezer for up to 2 months.

To Bake from Frozen: There’s no need to thaw the dough! Simply place the frozen dough balls on your lined baking sheets, spacing them 2-3 inches apart, and bake in a preheated oven. They will likely require an additional 1-2 minutes of baking time compared to fresh dough, so keep an eye on them until the tops are set and edges are golden.

Creative Variations & Customizations

While this classic monster cookie recipe is perfect as is, don’t hesitate to get creative with your mix-ins:

• Nut Butter Swaps: Experiment with almond butter or cashew butter for a different nutty flavor profile. Ensure the consistency is similar to commercial peanut butter.
• Nutty Additions: Stir in chopped pecans, walnuts, or peanuts for extra crunch and flavor.
• White Chocolate & Toffee: White chocolate chips or toffee bits can add another layer of sweetness and texture.
• Pretzel Pieces: For a sweet and salty twist, crush some pretzels and mix them into the dough.
• Dark Chocolate Chunks: Replace some or all of the chocolate chips with dark chocolate chunks for a more intense chocolate experience.

These monster cookies represent the perfect marriage of peanut butter, rich chocolate, and a wonderfully soft, chewy cookie base. You’ll adore how straightforward the recipe is and how incredibly satisfying these colossal cookies are to eat. So, pour yourself a generous glass of cold milk, gather your ingredients, and get ready to indulge in the most delicious cookie goodness!

More Delicious Cookie Recipes to Try

If you’re utterly smitten with these magnificent monster cookies, we highly recommend exploring some of our other cherished cookie recipes that are equally simple to make and incredibly delicious:

• Monster Cookie Bars: All the flavor of monster cookies in an easy-to-bake bar format.
• Soft & Chewy M&M Cookies: A classic, colorful cookie that’s always a crowd-pleaser.
• Oatmeal Peanut Butter Cookies: A comforting blend of hearty oats and rich peanut butter.
• Peanut Butter Chocolate Chip Cookies: The perfect duo of sweet and nutty flavors.
• Soft and Chewy Oatmeal Chocolate Chip Cookies: A wholesome and delicious twist on a classic.

Did you love baking these monster cookies? We’d be thrilled if you could rate the recipe and leave a comment below with your feedback and experience!