Flourless Monster Cookies Recipe with Oats and Chocolate Chips

These flourless Monster Cookies are destined to become your go-to treat. Built on a base of oats and creamy peanut butter, they’re loaded with semi-sweet chocolate chips and colorful M&M’s for every bite. Soft, chewy, and full of texture, they deliver classic cookie satisfaction without any flour.

These really are some of the best monster cookies you can make at home. The recipe is based on a beloved peanut butter and oatmeal cookie, then amped up with chocolate for a dessert everyone will reach for again and again.

What are monster cookies?

Monster cookies are large, soft cookies made from an oatmeal and peanut butter base, traditionally studded with chocolate chips and M&M’s. They’re known for being thick, chewy, and generously filled with mix-ins—hence the “monster” name.

Why you need to make these

Originating in the Midwest, monster cookies are especially popular where family baking traditions are strong. The combination of peanut butter, oats, and chocolate is irresistible. Here’s what makes this version stand out:

• Flourless: No flour is used—rolled or quick oats form the base, so these are naturally whole-grain and easy to make gluten-free when you choose certified gluten-free oats.
• Jam-packed: Every bite includes both chocolate chips and M&M’s for double the chocolate and color.
• Freezer-friendly: Make a double batch and freeze extras for up to three months, ready to bake or thaw and enjoy.
• Big cookies: These are generous cookies—each is about 2 heaping tablespoons of dough, resulting in satisfying, large cookies that are perfect for sharing.

Main ingredients for Monster Cookies

Oats: Because these cookies are flourless, oats do the heavy lifting. Use 2.5 cups of quick-cooking oats for the most traditional texture. Rolled oats will give a heartier chew.

Peanut butter: Creamy peanut butter provides flavor, structure, and moisture. Regular creamy peanut butter or all-natural varieties both work well—pick your favorite.

Chocolate chips: Semi-sweet chips are classic, but milk or dark chocolate can be used depending on how sweet or intense you want the chocolate flavor.

M&M’s: Colorful and crunchy, M&M’s add fun and variety to each bite. Use your preferred type.

Other ingredients

Besides oats, peanut butter, chocolate chips, and M&M’s, you’ll need:

• unsalted butter (melted)
• light brown sugar (packed)
• maple syrup
• 1 large egg
• vanilla extract
• baking soda
• a pinch of salt

Top tips for baking

After testing this recipe multiple times, these practical tips will help you get perfect cookies every time:

• Chill the dough: Refrigerate the mixed dough for about 20 minutes so it firms up and is easier to shape.
• Wet your hands: If the dough sticks while rolling, wet your hands slightly to prevent sticking and make shaping smoother.
• Pat down slightly: These cookies don’t spread excessively, so press each ball gently to form a cookie shape before baking.
• Watch for color: Bake until the edges begin to turn golden brown. Oven temperatures vary, so keep an eye to prevent overbaking.
• Cool completely: Straight from the oven the cookies will feel soft; allow them to cool on a wire rack for at least 10–20 minutes to firm up properly.

Recipe variations

• Nut butter: Swap peanut butter for almond or cashew butter for a different flavor profile.
• Extra mix-ins: Boost texture and flavor with additions like shredded coconut, chopped peanuts, butterscotch chips, or peanut butter chips.

Storage

Allow cookies to cool completely, then store them in an airtight container at room temperature in a cool, dark place for up to 5 days. For longer storage, freeze as described below.

Freezer instructions

These cookies freeze very well. Cool completely, then place in a freezer-safe bag or container. They keep for up to 3 months. Thaw at room temperature or warm briefly in a low oven before serving.

Best Monster Cookies — Recipe

Yields about 16 large cookies. Prep time: ~40 minutes (including chilling). Bake time: 11–14 minutes.

Ingredients

• 1/4 cup melted unsalted butter
• 1/2 cup light brown sugar, packed
• 2 tablespoons maple syrup
• 1 large egg
• 1/2 cup creamy peanut butter
• 1 teaspoon vanilla extract
• pinch of salt
• 2.5 cups quick-cooking oats (or rolled oats, gluten-free if desired)
• 1 teaspoon baking soda
• 1/2 cup semi-sweet chocolate chips
• 1/2 cup M&M’s

Instructions

1. Preheat the oven to 350°F (175°C). Line a baking sheet with parchment or lightly spray with nonstick spray.
2. In a mixing bowl, combine the melted butter and brown sugar, stirring until smooth and lump-free. Add the maple syrup, egg, peanut butter, and vanilla; mix until well combined.
3. Stir in a pinch of salt, the oats, and baking soda until everything is evenly incorporated. Fold in the chocolate chips and M&M’s.
4. Refrigerate the dough for about 20 minutes to firm up. This makes scooping and shaping easier.
5. Scoop roughly 2 heaping tablespoons of dough and form into a ball. Place on the prepared baking sheet and gently flatten to shape the cookie.
6. Space about 2 inches apart and repeat until you have up to six cookies per sheet (depending on sheet size).
7. Bake at 350°F for 11–14 minutes, or until the edges turn golden brown. Baking time can vary by oven—watch closely.
8. Remove from the oven and let the cookies rest on the baking sheet for a couple of minutes, then transfer to a wire rack to cool completely and firm up for 10–20 minutes.

Tips & Notes

• Because the dough is slightly sticky, moistening your hands before rolling helps. Rinse your hands between shaping balls if needed.
• If you don’t press the balls down before baking, you’ll get taller, dome-shaped cookies rather than flattened ones.