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Marshmallow Monster Cookies

Delightful cookies that combine chewy oats, rich chocolate, and gooey marshmallow fluff, perfect for nostalgic baking experiences.
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Prep Time 20 minutes
Cook Time 16 minutes
Total Time 40 minutes
Servings: 38 cookies
Course: Dessert, Snack
Cuisine: American
Calories: 220
Ingredients Method Notes

Ingredients
  

Wet Ingredients
  • 1 cup unsalted butter, room temperature Use Kerrygold for its creamy texture.
  • 1 cup creamy peanut butter Jif is recommended for ease of mixing.
  • 2 large eggs, room temperature
Dry Ingredients
  • 1.5 cups light brown sugar, packed
  • 2 cups all-purpose flour King Arthur Flour is preferred.
  • 1 cup old-fashioned oats
  • 1 teaspoon baking soda
  • 0.5 teaspoon kosher salt
Add-ins
  • 1.5 cups plain M&M candies
  • 1.5 cups semi-sweet chocolate chips Ghirardelli recommended.
  • 1 jar marshmallow fluff (7 ounces)
  • to taste none mini M&M candies, for topping Optional but recommended.

Method
 

Preparation
  1. Preheat your oven to 350°F (175°C) and line several baking sheets with parchment paper.
  2. In a stand mixer, beat the butter on medium-high speed until smooth (about 1 minute).
  3. Add the peanut butter to the butter and beat for about 2 minutes until smooth.
  4. Gradually add the brown sugar and mix on medium-high speed until well combined (about 2 minutes).
  5. Add the eggs one at a time, mixing for 30 seconds after each addition and scraping down the bowl.
  6. With the mixer off, add the flour, oats, baking soda, and salt. Mix on low until just combined.
  7. Gently fold in the M&M candies and chocolate chips until evenly distributed.
  8. Use a 2-tablespoon scoop to drop dough onto prepared baking sheets and flatten each into a disk.
  9. Place a tablespoon of marshmallow fluff in the center of each disk and top with a second disk, sealing the edges.
  10. Sprinkle each cookie with mini M&Ms if desired.
Baking
  1. Bake for 15-16 minutes or until edges are golden brown and centers are still soft.
  2. Let the cookies cool completely on the baking sheets before serving.

Notes

For softer cookies, remove them from the oven when edges are golden but the center appears slightly underbaked. Chilling the dough can enhance texture. Store in an airtight container at room temperature for 4-5 days or freeze for up to 3 months.