These Monster Cookies are packed with creamy peanut butter, hearty old-fashioned oats, semi-sweet chocolate chips, and milk chocolate M&M candies. They’re soft, chewy, and loaded with all the chocolate and peanut butter goodness you want in a cookie.
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In college, my roommate would make Monster Cookies and we’d all devour them that night. She never shared the recipe, so I eventually had to come up with my own version. These cookies always bring back those memories, and I love that baking can do that—connect a recipe to a time and place you remember.
If you love peanut butter cookies, oatmeal cookies, and M&M cookies, you’re going to love these easy Monster Cookies.
What Are Monster Cookies?
Monster Cookies are a delicious combination of several classic cookie ingredients. They have the peanut butter flavor of a peanut butter cookie, the hearty texture of an oatmeal cookie, and plenty of chocolate from semi-sweet chocolate chips and M&Ms.
There’s a lot going on in these cookies, and that’s exactly what makes them Monster Cookies!
What’s in Monster Cookies?
Unsalted butter: A staple ingredient in cookies! I use unsalted butter so I can control the amount of salt in the recipe.
Granulated sugar and brown sugar: The combination of these two sugars creates a sweet, chewy cookie with plenty of flavor.
Creamy peanut butter: There is almost a cup of peanut butter in these cookies, so you can really taste it. I recommend using creamy peanut butter for the smoothest texture.
Eggs: Eggs help bind the ingredients together and give the cookies structure.
Vanilla extract: A little vanilla adds extra flavor and brings all the other ingredients together.
All-purpose flour, salt, baking soda, and baking powder: These ingredients provide the structure and help the cookies rise as they bake.
Old-fashioned oats: I prefer old-fashioned oats in these Monster Cookies because they give the cookies a hearty texture and flavor. I found that they worked better than quick oats in this recipe.
Semi-sweet chocolate chips and M&Ms: I love using semi-sweet chocolate chips to balance the sweetness of the M&Ms. Together, they give these cookies plenty of chocolate in every bite.
How to Make Monster Cookies
1. Cream the butter, sugars, and peanut butter: Just like most cookie recipes, start by creaming the butter, brown sugar, and granulated sugar until the mixture is light and fluffy. Add the peanut butter and mix until smooth.
2. Add the eggs and vanilla: Add the eggs one at a time, mixing well after each addition. Scrape down the sides of the bowl as needed so everything mixes evenly. Add the vanilla and mix until combined.
3. Add the dry ingredients: Add the flour, salt, baking soda, baking powder, and old-fashioned oats. Mix on low speed just until the ingredients are combined. Be careful not to overmix the dough.
4. Add the chocolate: Now it’s time for the best part! Add the semi-sweet chocolate chips and M&Ms. Mix on low speed just until they are evenly distributed throughout the dough.
5. Scoop and bake: Portion about 3 tablespoons of dough for each cookie and roll into balls. Place the cookie dough balls on a parchment-lined baking sheet about 2 inches apart. Bake at 350°F for 10–12 minutes. The centers should still look slightly soft when you take them out of the oven. Let the cookies cool on the baking sheet for 5–10 minutes before transferring them to a wire rack.
Helpful Baking Equipment
- Stand Mixer: I love my KitchenAid mixer.
- Kitchen Scale: These kitchen scale has great reviews.
- Measuring cups and spoons: I use and love this set of measuring cups and spoons.
- Rubber spatula: These rubber spatulas are a best seller.
- Rimmed baking sheets: I love these Nordic Ware baking sheets.
- Cookie Scoop: I love and use this cookie scoop set.
- Parchment paper: Using parchment paper makes for a better cookie and easier to clean up.
Tips for Making Monster Cookies
Don’t overmix the dough. Once you add the flour, mix just until the ingredients are combined. Overmixing can make cookies tough instead of soft and chewy.
Use old-fashioned oats. I prefer old-fashioned oats for these cookies because they give them a hearty texture without making them too dense.
Don’t overbake. The cookies should still look slightly soft in the centers when they come out of the oven. They will continue to set as they cool.
Measure your flour carefully. For the most consistent results, use a kitchen scale to measure your flour. If you’re using measuring cups, spoon the flour into the cup and level it off rather than scooping directly from the flour container.
How to Store Monster Cookies
Store Monster Cookies in an airtight container at room temperature for up to 5 days. They are best within the first 2–3 days.
Can You Freeze Monster Cookie Dough?
Yes! Scoop the cookie dough into individual portions and place the dough balls on a parchment-lined baking sheet. Freeze until solid, then transfer the frozen dough balls to an airtight freezer-safe container or bag.
When you’re ready to bake them, place the frozen dough balls on a parchment-lined baking sheet and bake as directed, adding a few extra minutes to the baking time if needed.
More Recipes You’ll Love
- Delicious Oatmeal Milk Chocolate Chip Cookies
- Amazing Peanut Butter Chip Cookies
- Levain Copycat Caramel Coconut Chocolate Chip Cookies
Monster Cookies
Equipment
- Rimmed baking sheets
- parchment paper
- Measuring cups and spoons
- Stand mixer or hand mixer
- Silicone spatula
- Kitchen scale
Ingredients
- ½ cup (113.5 g) unsalted butter, slightly cold
- ¾ cup (159 g) light brown sugar, packed
- ¼ cup (50 g) granulated sugar
- ¾ cup (192 g) creamy peanut butter
- 2 (100 g) large eggs, room temperature
- 1 teaspoon vanilla extract
- 1½ cups (180 g) all-purpose flour
- ½ teaspoon salt
- 1 teaspoon baking soda
- ½ teaspoon baking powder
- 2½ cups (200 g) old-fashioned oats
- 1 cup (170 g) semi-sweet chocolate chips
- 1 cup (175 g) M&Ms, plain
Instructions
- Preheat the oven: Preheat the oven to 350°F (175°C). Line rimmed baking sheets with parchment paper and set aside.
- Cream the butter, sugars, and peanut butter: In the bowl of a stand mixer fitted with the paddle attachment, beat the butter until smooth. Add the brown sugar and granulated sugar and beat until light and fluffy, about 2–3 minutes. Add the peanut butter and mix until smooth.
- Add the eggs: Add the eggs one at a time, mixing until smooth after each addition. Scrape down the sides of the bowl after adding each egg.
- Add the vanilla: Add the vanilla extract and mix for about 20–30 seconds.
- Add the dry ingredients: With the mixer on low speed, add the all-purpose flour, salt, baking soda, baking powder, and old-fashioned oats. Mix just until the ingredients are combined. Be careful not to overmix.
- Add the chocolate: Add the semi-sweet chocolate chips and M&Ms. Mix on low speed just until incorporated.
- Portion the dough: Portion about 3 tablespoons of dough and roll into balls. Place the dough balls on the prepared baking sheet about 2 inches apart.
- Bake: Bake for 10–12 minutes. The edges should look set while the centers still look slightly soft.
- Cool: Let the cookies cool on the baking sheet for 5–10 minutes. Transfer them to a wire cooling rack to finish cooling.
