Turn an ordinary cookie craving into something big with these Peanut Butter Monster Cookies loaded with your favorite sweet mix-ins.
These Peanut Butter Monster Cookies combine rich, nutty flavor, tender oats, and colorful M&M’s in a soft, chewy treat. Brown sugar adds a warm sweetness, while the candy shells bring a little crunch to every chocolate-filled bite.
I absolutely love Monster Cookies, I could snack on them all day! Who can resist a cookie packed with peanut butter and M&Ms? For a fun twist, you have to also try my Gluten-Free Monster Cookies or Dark Chocolate Monster Cookies.
Table of Contents
Why You’ll Love These Monster Cookies
- Melted butter and peanut butter create rich, chewy centers without requiring softened butter or extended creaming.
- Brown and granulated sugars balance moisture, caramel flavor, sweetness, and create lightly crisp cookie edges.
- One and one-half cups of colorful candy pieces ensure chocolate and crunch in every bite!.
- The dough needs no refrigeration, so you can make these cookies and enjoy them in less than 30 minutes!
Recipe Ingredients
Peanut Butter – Smooth peanut butter works best for this recipe. I highly recommend using regular creamy peanut butter, such as Jif or Skippy, for the best texture. Chunky peanut butter adds crunch but changes the consistency.
M&Ms – You can use regular, mini, or even seasonal M&M candies for a fun variation. They add a sweet, chocolatey crunch and a pop of color, making these cookies extra appealing.
Chocolate Chips – Semi-sweet chocolate chips are the classic choice, but milk chocolate or dark chocolate chips work just as well.
For a full list of ingredients and amounts, see the recipe card below.
Variations
Fun Mix-In Options – Try adding Reese’s Pieces, toffee bits, crushed pretzels, shredded coconut, mini marshmallows, or chopped nuts for extra texture and flavor. Keep total mix-ins under 2 cups to maintain the right dough consistency.
Dried Cranberries or Raisins – Introduce a chewy, sweet-tart element by adding dried cranberries or raisins.
How to Make Peanut Butter Monster Cookies
Step 1: In a large mixing bowl or the bowl of a stand mixer, beat together the peanut butter, butter, sugars, and vanilla extract. Add the egg and egg yolk, and mix until combined.
Step 2: In a medium mixing bowl, whisk together the oats, flour, salt, and baking soda. Gradually add the dry ingredients to the wet ingredients. Mix until a soft dough forms. Fold in the M&Ms with a spatula.
Step 3: Let the cookie dough stand for 15 minutes to allow the oats to absorb excess moisture.
Step 4: Meanwhile, preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius), and line baking sheets with parchment paper or baking mats.
Step 5: Using a standard-size cookie scoop (#40 or 1.5 tbsp.), scoop balls of dough and place them onto the prepared sheets. Gently pat to slightly flatten. Place the cookie dough balls in the oven and bake for 10–12 minutes, taking care not to overbake. The cookies will look soft, but allow them to cool on the sheets for 5 minutes before transferring them to a wire rack to cool completely.
FAQs
Yes! Semi-sweet chocolate chips are the classic choice, but you can use milk chocolate, dark, or even white chocolate chips. Peanut butter or butterscotch chips also work well if you want a different flavor twist.
Yes, you can use old-fashioned oats, but the texture will be chewier and bulkier. To achieve a consistency closer to quick oats, pulse the old-fashioned oats in a food processor a few times to break them into smaller pieces.
Storage Information
STORE Peanut Butter Oatmeal Monster Cookies in an airtight container or resealable bag at room temperature to keep them soft and fresh for up to 1 week. To prevent them from drying out, place a slice of bread in the container—the cookies will absorb moisture while the bread becomes stale.
FREEZE either the cookie dough or baked cookies for longer storage. For dough, roll into balls, pre-freeze on a baking sheet until firm, then transfer to a freezer-safe bag. The dough lasts up to 3 months and can be baked straight from frozen—just add 1–2 extra minutes to the baking time.
For baked cookies, let them cool completely before layering them in a freezer-safe bag with parchment paper between them. Thaw at room temperature or warm in the microwave for 10–15 seconds for a soft, fresh-baked texture.
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Peanut Butter Monster Cookies Recipe
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Ingredients
- 1/2 cup peanut butter - creamy or crunchy
- 1/2 cup unsalted butter - melted
- 1/4 cup granulated sugar
- 3/4 cup brown sugar
- 2 tsp vanilla extract
- 1 egg
- 1 egg yolk
- 2 cup quick oats - not old-fashioned
- 3/4 cup all-purpose flour
- 1/2 tsp salt
- 1/2 tsp baking soda
- 1 1/2 cup M&Ms - regular, mini m&m, or mix of both
- 1/2 cup chocolate chips - OR peanut butter chips OR chopped peanuts(optional)
Instructions
- In a large mixing bowl or the bowl of a stand mixer, beat together the peanut butter, butter, sugars, and vanilla extract. Add the egg and egg yolk, and mix until combined.
- In a medium mixing bowl, whisk together the oats, flour, salt, and baking soda. Gradually add the dry ingredients to the wet ingredients. Mix until a soft dough forms. Fold in the M&Ms with a spatula.
- Let the cookie dough stand for 15 minutes to allow the oats to absorb excess moisture.
- Meanwhile, preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius), and line baking sheets with parchment paper or baking mats.
- Using a standard-size cookie scoop (#40 or 1.5 tbsp.), scoop balls of dough and place them onto the prepared sheets. Gently pat to slightly flatten. Place the cookie dough balls in the oven and bake for 10–12 minutes, taking care not to overbake. The cookies will look soft, but allow them to cool on the sheets for 5 minutes before transferring them to a wire rack to cool completely.
Delicious!! We are making cookies weekly around here & these are one of our favorites to make! Love the m&m’s with the peanut butter & oats! Everyone loves them!
These are always a hit with my family. The flavor and the color is so fun. The perfect combo!
My kids love cookies like this. They look so delicious!
I love cookies with M&M’s in them, they have such a wonderful flavor.
These are some gorgeous cookies. I think the M&M’s make these cookies very exciting and quite pretty! I could take a dozen of those guys off your hands and a glass of milk. 🙂