These chewy Monster Cookies are packed with peanut butter, old-fashioned oats, M&M’s and chocolate chips for a delightfully nostalgic treat. They have a tender, chewy center with a bit of crunch from the oats and the candies, and because there is no flour in the batter, they are naturally gluten-free when you use certified gluten-free oats. They bake up quickly and are a crowd-pleaser for snack time, lunchboxes, bake sales, or whenever you need a comforting cookie that tastes like childhood.
Chewy Monster Cookies
These cookies combine classic flavors—peanut butter and chocolate—with hearty oats and colorful M&M’s. The texture is chewy and slightly sticky in the middle, with browned, slightly crisp edges. Because the recipe relies on oats rather than wheat flour, it’s a great option for anyone avoiding gluten (use certified gluten-free oats to be safe). The recipe scales well, and you can easily swap or adjust the mix-ins to suit your tastes: all chocolate chips, all M&M’s, or a blend of both.
Ingredients Needed to Make These Cookies
- Butter, room temperature
- Brown sugar
- Granulated sugar
- Eggs, room temperature
- Vanilla extract
- Baking soda
- Creamy peanut butter
- Old-fashioned oats (use certified gluten-free oats if you need the cookies to be gluten-free)
- Chocolate chips
- M&M’s (or similar candy-coated chocolate pieces)
- Flaked sea salt, for sprinkling
How to Make Chewy Monster Cookies
- Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
- In a stand mixer or with a hand mixer, cream the butter, brown sugar and granulated sugar together until smooth and fluffy, about 3–4 minutes. Scrape the bowl as needed so everything incorporates evenly.
- Add the eggs one at a time, mixing well after each addition. Stir in the vanilla, peanut butter and baking soda, then mix on medium speed until the dough is uniform and smooth.
- Fold in the old-fashioned oats, M&M’s and chocolate chips until the mix-ins are evenly distributed.
- Use a medium to large cookie scoop to portion the dough. A 3-tablespoon scoop produces a medium cookie size; you can make them smaller or larger—just adjust bake time accordingly.
- Place the scooped dough on the prepared baking sheets with space between each cookie. Lightly press a few extra M&M’s or chips on top for presentation, and sprinkle a little flaked sea salt on each cookie if desired.
- Bake for approximately 8–10 minutes, depending on the cookie size, until the edges are lightly golden and the tops are set but still soft. For larger scoops, bake a few minutes longer. Remove from the oven and let cookies cool on the baking sheet for several minutes before transferring to a wire rack to cool completely.
Helpful Tips for Best Results
- For gluten-free cookies: confirm that your oats are certified gluten-free since oats can be cross-contaminated with wheat during processing.
- Bring butter and eggs to a slightly cool room temperature before mixing—about 15–30 minutes on the counter helps them blend smoothly without becoming greasy.
- Mix-ins are flexible: feel free to use different types of chocolate, nuts, or candies. A mix of chocolate chips and M&M’s gives both texture and color.
- Use parchment paper or a silicone baking mat to prevent excessive spreading and to keep bottoms from browning too quickly.
- Watch the bake time carefully. These cookies are best when the center remains chewy; they will continue to set slightly as they cool on the baking sheet.
Notes and Variations
If you prefer a softer, more cake-like cookie, increase the oats slightly or reduce the baking time by a minute or two. For chewier cookies, do not overbake—pull them from the oven when the tops look set but still a bit glossy. You can swap crunchy peanut butter for creamy if you like extra texture, or use almond or sunflower seed butter for a peanut-free version. Measurements are given in cups and grams; grams provide more consistent, precise results if you have a kitchen scale.
Nutrition (per cookie, approximate)
- Calories: 240 kcal
- Carbohydrates: 31 g
- Protein: 5 g
- Fat: 12 g
- Sugar: 21 g
- Fiber: 2 g
These Chewy Monster Cookies are an easy, flexible recipe that brings simple ingredients together into a familiar, satisfying cookie. They’re perfect for feeding a crowd or keeping on hand for quick sweet cravings. If you bake a batch, let them cool a bit so the centers set and enjoy warm or at room temperature.