Monster Cookies are the kind of treat that makes you feel like a kid again the second you see them. Oversized, chewy, and stuffed with colorful M&Ms, chocolate chips, oats, and peanut butter — they’re not subtle, and that’s exactly the point.
I love baking these when I want something fun and over-the-top. They’re a hit at bake sales, potlucks, or anytime you want to surprise someone with a cookie that’s guaranteed to make them smile.
This recipe is my tried-and-true favorite. It hits that perfect balance between soft and chewy, with just enough crunch from the candies and chocolate chips. Best of all? It’s easy to mix up in one bowl — no fancy steps required.
Why Are They Called Monster Cookies?
Monster Cookies got their name because they’re “monstrous” in the best way: big, packed with mix-ins, and impossible to ignore.
They’re what happens when you can’t decide between peanut butter cookies, oatmeal cookies, and chocolate chip cookies — so you throw everything in. The result is rich, chewy, and full of texture and flavor.
If you’ve never made them, you’re in for a treat. And if you have? Well, you know how hard it is to stop at just one.
What Makes These Monster Cookies So Good
It all starts with creamy peanut butter, which gives them richness and keeps them moist. Rolled oats add hearty chew and substance. Brown sugar ensures they stay soft, while just enough flour holds them together.
Then come the goodies: chocolate chips and M&Ms (or candy-coated chocolates of your choice). They melt, crunch, and add colorful fun to every bite.
These cookies are thick, satisfying, and designed to be shared — though you might want to keep a few extra for yourself.
My Favorite Ingredients for Monster Cookies
Creamy peanut butter is essential. It adds that classic flavor and helps the dough stay rich and soft. Old-fashioned rolled oats give these cookies their signature chew, while brown sugar deepens the flavor with molasses notes.
Butter keeps everything tender and rich. Eggs bind the dough and help it rise just enough without losing that dense, chewy center.
M&Ms are the classic choice for color and crunch, but I also love adding semi-sweet chocolate chips for extra chocolatey goodness. You can easily swap in peanut butter chips, chopped nuts, or whatever you love.
Ingredients
- 1/2 cup (1 stick) unsalted butter, softened
- 1 cup creamy peanut butter
- 1 cup packed brown sugar
- 1/2 cup granulated sugar
- 2 large eggs
- 2 tsp vanilla extract
- 1 1/2 cups old-fashioned rolled oats
- 1 cup all-purpose flour
- 1 tsp baking soda
- 1/2 tsp salt
- 3/4 cup semi-sweet chocolate chips
- 3/4 cup M&Ms (plus extra for topping)
Preheat the Oven
Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper for easy cleanup.
Cream the Butter, Peanut Butter, and Sugars
In a large mixing bowl, beat the softened butter, creamy peanut butter, brown sugar, and granulated sugar until light and fluffy. This step is essential for creating that soft, chewy texture Monster Cookies are famous for.
Add Eggs and Vanilla
Add the eggs one at a time, beating well after each addition. Pour in the vanilla extract and mix until smooth. The dough should be creamy and smell like pure cookie heaven.
Combine the Dry Ingredients
In a separate bowl, whisk together the all-purpose flour, baking soda, salt, and rolled oats. Mixing the oats with the flour ensures they’re evenly distributed and don’t clump in the dough.
Mix Wet and Dry
Gradually add the dry ingredients to the wet mixture, stirring until just combined. Don’t overmix — just enough to pull it all together into one cohesive, glorious dough.
Add the Goodies
Fold in the semi-sweet chocolate chips and M&Ms. The dough should be thick, studded with colorful candy and melty chocolate bits. If you want them extra “monstrous,” add a few extra M&Ms on top of each cookie before baking.
Scoop and Bake
Use a large cookie scoop or about 2 tablespoons of dough to form balls. Place them on your prepared baking sheets, leaving a couple of inches between each for spreading.
Bake for 10–12 minutes, or until the edges are set and the tops look just golden. The centers will look slightly underdone, which is perfect for that soft, chewy finish.
Cool Slightly
Let the cookies rest on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely. This short rest helps them firm up without losing their tender centers.
Tips for Perfect Monster Cookies
Use old-fashioned rolled oats for the best texture. Quick oats will make the cookies softer and cakier, while rolled oats keep them wonderfully chewy.
Don’t overbake. They should look just set in the middle when you pull them from the oven. They’ll continue to cook slightly on the baking sheet.
If you want extra color and crunch, press a few M&Ms onto the tops of the dough balls before baking. They’ll stay visible and add that bakery-style finish.
Monster Cookies freeze beautifully. Scoop the dough onto trays, freeze, then store in a freezer bag. Bake straight from frozen with a minute or two added to the bake time.
Storing Your Cookies
Once cooled, store the cookies in an airtight container at room temperature for up to 5 days. They stay soft and chewy for days, making them perfect for lunches or snacks.
For longer storage, freeze baked cookies in a freezer bag for up to 3 months. Thaw at room temperature or microwave briefly for a warm, melty treat.
Final Thoughts
Monster Cookies are the ultimate “everything but the kitchen sink” cookie. They’re fun, colorful, satisfying, and perfect for sharing — or not.
I love making these with kids (they go crazy for the M&Ms), for potlucks, or just for a little nostalgic joy on an ordinary day.
If you try them, let me know how they turn out! And tell me what goodies you added in — these cookies are endlessly customizable and always a hit.
Ingredients
Method
- Line two baking sheets with parchment paper for easy cleanup.
- In a large mixing bowl, beat the softened butter, creamy peanut butter, brown sugar, and granulated sugar until light and fluffy.
- Add the eggs one at a time, beating well after each addition. Pour in the vanilla extract and mix until smooth.
- In a separate bowl, whisk together the all-purpose flour, baking soda, salt, and rolled oats.
- Gradually add the dry ingredients to the wet mixture, stirring until just combined.
- Don’t overmix — just enough to pull it all together into one cohesive, glorious dough.
- Fold in the semi-sweet chocolate chips and M&Ms. The dough should be thick, studded with colorful candy and melty chocolate bits.
- Use a large cookie scoop or about 2 tablespoons of dough to form balls.
- Place them on your prepared baking sheets, leaving a couple of inches between each for spreading.
- Bake for 10–12 minutes, or until the edges are set and the tops look just golden.
- Let the cookies rest on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.
