Disclosure: This post may contain affiliate links. I may earn a small commission for my endorsement, recommendation, testimonial, and/or link to any products or services from this website.
With crisp, golden brown edges and thick, soft and chewy centers, these are the best monster cookies you’ll ever taste! The flourless peanut butter oatmeal cookies are studded with chocolate chips and M&M’s for a sweet and salty combination that’s perfect alongside a cold glass of milk.
What are monster cookies made of?
Monster cookies are flourless peanut butter cookies made with oatmeal, M&M’s, and chocolate chips. It’s that classic sweet and salty combination that’s absolutely irresistible! We particularly love this recipe because the dough yields thick, soft, and chewy cookies that are loaded with rich peanut butter flavor.
Ingredients
This is just a quick overview of the ingredients that you’ll need for the best monster cookies recipe. As always, specific measurements and step-by-step instructions are included in the printable recipe box at the bottom of the post.
- Butter: I prefer salted butter for the extra flavor. Don’t forget to allow plenty of time for your butter to soften at room temperature, which makes it easier to cream together with the sugar.
- Light brown sugar and granulated sugar: by using slightly more brown sugar than granulated sugar, you get a softer, chewier cookie.
- Creamy peanut butter: a processed brand, such as Jif or Skippy, works best. Do not use natural peanut butter.
- Large eggs: give the cookies structure.
- Corn syrup: this liquid sweetener yields a chewier cookie.
- Vanilla extract: for warm flavor.
- Baking soda: the leavening agent that helps the cookies puff up.
- Salt: to balance the sweetness and enhance the other flavors in the cookies.
- Quick-cooking oats: this oatmeal is more processed than old-fashioned oats, so the oats are smaller, which provides a better texture for the cookies. The oats take the place of flour as the base of the cookie dough.
- Chocolate chips: we like semi-sweet chocolate chips, but you can use dark chocolate chips, white chocolate chips, butterscotch chips, or milk chocolate chips — whichever you prefer.
- M&M candies: change up the variety of M&Ms to suit the season! For instance, use red and green M&M’s for Christmas cookies, or try Reese’s pieces at Halloween.
How to Make Monster Cookies
These flourless peanut butter cookies come together with just 10 minutes of hands-on prep. They’re sweet, salty, and totally kid-friendly!
- Mix together the cookie dough with the paddle attachment in the large bowl of a stand mixer, or with a hand mixer in a large mixing bowl.
- Chill the dough in the fridge for a couple of hours (or overnight).
- Scoop the dough, and top the cookie dough balls with extra m & m candies and chocolate chips if you like.
- Bake for about 10 minutes, then enjoy!
How to Keep Monster Cookies Soft
The key to maintaining those decadent, soft centers in your cookies is not overbaking. Remove the cookies from the oven just as the edges are starting to brown. The centers will still look soft and under-baked, but the cookies will continue to firm up as they cool.
Preparation and Storage
Store the baked cookies in an airtight container at room temperature. They will last on the counter for about 3 days. To extend the life of your cookies, wrap them tightly and freeze them for up to 3 months.
How long does Monster cookie dough last in the fridge?
You’ll want to chill the dough for at least 2 hours, which makes it less sticky and easier to scoop. The chilled dough also holds its shape better in the oven so that your cookies don’t spread too thin. The dough will last in the fridge in an airtight container or covered bowl for up to 24 hours.
How to Freeze Monster Cookie Dough
Scoop the cookie dough into round balls, top with additional chocolate chips and M&Ms, and then freeze the cookie dough on a parchment-lined baking sheet for 1-2 hours, or until firm. Once the dough is frozen, package the dough balls in airtight containers or in a freezer-safe Ziploc bag.
Store the dough in the freezer for up to 3 months. When ready to bake, arrange the frozen dough on baking sheets and bake according to the recipe instructions, adding 1-2 minutes to the total baking time since you’re starting with frozen dough.
Recipe Variations
- This recipe yields a very large batch of cookies. If you prefer a smaller batch, cut all of the ingredients in half.
- Substitute with crunchy peanut butter if you like little bits of crunchy peanuts in your cookies.
- Try other add-ins for this classic monster cookie recipe, such as chopped, salted, roasted peanuts or shredded coconut.
- Semi-sweet chocolate chips are the classic addition to monster cookies; however, you can substitute with any chocolate chips that you like. Try milk chocolate chips, dark chocolate chips, white chocolate chips, chocolate chunks, coarsely-chopped chocolate bars, or even butterscotch chips.
- To make giant monster cookies, use an ice cream scoop to shape the dough. The giant cookies will need a couple of extra minutes in the oven.
Tips for the Best Monster Cookie Recipe
- Line the Baking Sheets. Spraying the baking sheets with cooking spray or greasing with butter or lard creates a slippery surface that causes cookies to spread. Instead, line the baking sheets with parchment paper or a silicone mat (silpat) for “grip,” so that the cookies stay thick and chewy.
- Why did my monster cookies go flat? Allow plenty of time for your cookie dough to chill in the fridge (at least 2 hours). If the dough is too warm, it’s harder to scoop, and the cookies will spread more in the oven.
- When the dough is properly chilled, these cookies do not spread very much. Use a fork to gently press down on the dough balls before baking if you prefer thinner cookies.
- Use a processed peanut butter (like Jif or Skippy) rather than all-natural peanut butter. The processed nut butters do not separate, which yields a better quality cookie.
- For soft and chewy monster cookies, pull the cookies out of the oven when they still look slightly under-baked in the center. They will firm up as they cool, but will remain nice and chewy on the inside.
- The cook time is just an estimate, and will vary depending on your specific oven. Keep a close eye on the cookies and pull them out when they are set and lightly golden brown on the edges. Don’t overbake, or you’ll end up with crunchy cookies!
More Cookie Recipes to Try
Monster Cookies
Ingredients
- ½ cup salted butter, softened at room temperature
- 1 ¼ cups packed light brown sugar
- ¾ cup granulated sugar
- 1 ½ cups creamy peanut butter (such as Jif or Skippy brand)
- 3 eggs
- 1 teaspoon corn syrup
- 1 teaspoon vanilla extract
- 2 teaspoons baking soda
- ½ teaspoon salt
- 4 ½ cups quick-cooking oats
- 1 cup chocolate chips, plus extra for topping
- 1 cup M&M’s candies, plus extra for topping
Instructions
- In a large bowl, use a hand mixer or an electric stand mixer to cream together the butter, brown sugar, and granulated sugar until light and fluffy, about 2-3 minutes.
- Add the peanut butter; mix well. Add the eggs, one at a time, and then the corn syrup and the vanilla extract; mix to combine.
- Sprinkle in the baking soda and salt; mix to combine.
- Mix in the oats until completely combined.
- Fold in the chocolate chips and M&M’s.
- Cover the bowl and chill the dough in the refrigerator for at least 2 hours or overnight.
- Preheat the oven to 350°F.
- Use a cookie scoop or a tablespoon to drop the dough onto parchment-lined or silicone-lined baking sheets. Once the dough is chilled, these cookies will not spread too much in the oven. If you prefer a thinner cookie, use a fork to gently press down on the dough balls to flatten them slightly.
- Gently press additional M&Ms and chocolate chips into the tops of the cookie dough, if desired.
- Bake the cookies until the edges are set and beginning to brown, but the centers are still soft and puffy, about 10 minutes. The cookies will continue to firm up as they cool, so be sure that you don’t overbake them or they’ll be tough and crunchy.
- Use a spatula to transfer the cookies directly to wire rack. Let cool for at least 5 minutes, then enjoy!
Notes
- Line the Baking Sheets. Spraying the baking sheets with cooking spray or greasing with butter or lard creates a slippery surface that causes cookies to spread. Instead, line the baking sheets with parchment paper or a silicone mat (silpat) for “grip,” so that the cookies stay thick and chewy.
- Why did my monster cookies go flat? Allow plenty of time for your cookie dough to chill in the fridge (at least 2 hours). If the dough is too warm, it’s harder to scoop, and the cookies will spread more in the oven.
- When the dough is properly chilled, these cookies do not spread very much. Use a fork to gently press down on the dough balls before baking if you prefer thinner cookies.
- Use a processed peanut butter (like Jif or Skippy) rather than all-natural peanut butter. The processed nut butters do not separate, which yields a better quality cookie.
- For soft and chewy monster cookies, pull the cookies out of the oven when they still look slightly under-baked in the center. They will firm up as they cool, but will remain nice and chewy on the inside.
- The cook time is just an estimate, and will vary depending on your specific oven. Keep a close eye on the cookies and pull them out when they are set and lightly golden brown on the edges. Don’t overbake, or you’ll end up with crunchy cookies!
Nutrition
What size cookie scoop did you use for your cookies?
Hi, Corrine! I use a standard cookie scoop that measures 1.5 inches in diameter.