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If you’re looking for the ultimate cookie recipe that combines all your favorite treats into one giant, chewy, and perfectly sweet bite—look no further than Old Fashioned Monster Cookies!

These colorful, peanut butter-loaded cookies are packed with oats, chocolate chips, and M&Ms, making them an irresistible treat for both kids and adults.

Whether you’re baking for a holiday, a school event, or just a cozy weekend at home, these cookies are a fun and easy recipe to whip up. Let’s dive in!

🧁 What Are Monster Cookies?

Monster Cookies are basically the “everything” cookie. They combine the best of chocolate chip, oatmeal, and peanut butter cookies into one glorious dessert. Traditionally made with oats, peanut butter, chocolate chips, and M&Ms, they’re big, chewy, and bursting with color.

They’re called “monster” cookies not just because of their size, but because they’re monstrously delicious!

🍪 Ingredients You’ll Need

Here’s what you’ll need to make a batch of these scrumptious cookies:

• 1 cup creamy peanut butter
• 1 cup of sugar
• 2 large eggs
• 1 cup of oats
• 1/4 teaspoon salt
• 1/2 cup of chocolate chips
• 1/2 cup of Plain M&M's

Optional mix-ins: Mini marshmallows, crushed pretzels, peanut butter chips, or chopped nuts for an extra twist.

🥣 Step-by-Step Instructions

Step 1: Preheat the Oven

Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone baking mats.

Step 2: Mix the ingredients

In a large bowl, beat together the peanut butter, sugar, and eggs.

Step 3: Add the Dry Ingredients

Mix in the oats and salt until fully incorporated. You’ll notice this dough is thicker than typical cookie dough—that’s what makes Monster Cookies so hearty!

Step 5: Stir in the Goodies

Fold in your chocolate chips and M&Ms (and any other add-ins you love).

Step 6: Scoop and Bake

Using a cookie scoop or tablespoon, drop dough balls onto your prepared baking sheets about 2 inches apart.
Bake for 10–12 minutes, just until the edges start to turn golden brown. The centers will still look soft—that’s perfect!

Step 7: Cool and Enjoy

Let cookies cool on the baking sheet for about 5 minutes before transferring them to a wire rack.

👩‍🍳 Tips for the Best Monster Cookies

• Don’t overbake! They’ll firm up as they cool.
• Switch up the candy: Try peanut butter M&Ms, mini Reese’s Pieces, or even holiday-colored M&Ms for seasonal fun.
• Make them extra big: Use a ¼ cup measuring scoop for bakery-style “monster-sized” cookies.
• Storage: Keep cookies in an airtight container for up to 5 days, or freeze them for up to 3 months.

🎃 Fun Variations

• Halloween Monster Cookies: Use orange, purple, and green M&Ms.
• Christmas Monster Cookies: Add red and green M&Ms and white chocolate chips.
• Valentine’s Day Cookies: Use pink and red M&Ms with heart sprinkles.

❤️ Why You’ll Love This Recipe

Monster Cookies are:

• Easy to make in one bowl
• Naturally gluten-free (thanks to oats, not flour)
• Chewy, soft, and loaded with texture
• Totally customizable

Whether you’re baking them for a family gathering, a school bake sale, or just because you’re craving something sweet, these Monster Cookies will be a hit every single time.

Grab your favorite mix-ins, preheat that oven, and let the cookie magic begin!

Love Cookie Recipes? Check These Out!

• Gingerbread Cookies
• Italian Ricotta Cookies
• Kitchen Sink Cookies