Peanut Butter M&M Cookies – Deliciously thick, chewy, and soft peanut butter loaded cookies that are stuffed full of chocolate M&M’s. These are the absolute BEST peanut butter cookies!

Peanut Butter M&M Cookies
You just can’t beat a thick, soft, and incredibly chewy peanut butter cookie. Especially if they are also loaded with chocolate M&M’s!
And that is exactly what these cookies are.
They are so full of flavour, and with the added crunch from the M&M’s, makes them my absolute favourite peanut butter cookie.
If you’re a big peanut butter fan (and love M&M’s), then I think you are going to LOVE these cookies!
Looking for more peanut butter recipes? Check out my Peanut Butter Cup Brownies, Chocolate Peanut Butter Bark, and my Peanut Butter & Jam Muffins.

Ingredients you’ll need
Here’s a list of ingredients you’ll need to make these cookies. You can find my recipe card at the bottom of this post for the complete list with their amounts.
- Plain/all-purpose flour
- Baking powder
- Baking soda
- Cornflour/cornstarch: Makes for extra soft and thick cookies.
- Salt
- Unsalted butter: Melted.
- Light brown sugar: Using mostly brown sugar makes for extra chewy cookies with a deeper flavour.
- Caster/granulated sugar
- Large egg
- Vanilla extract
- Smooth peanut butter: Microwaved until runny – about 20 seconds.
- Chocolate M&M’s
How to make Peanut Butter M&M Cookies
To make these cookies, simply grab a medium mixing bowl and whisk together the flour, baking powder, baking soda, cornflour, and salt. Set aside.

In a separate large mixing bowl, whisk together the melted butter and sugars until combined.

Add the egg, vanilla extract, and peanut butter, and mix until combined.

Add the dry ingredients, mix until just combined, then fold in the M&M’s.

TIP: If you find the cookie dough too crumbly, add milk (1 tablespoon at a time) and mix until it comes together and is easier to manage.

Roll the dough into 2-oz balls (or use a medium cookie scoop), and place onto a baking tray lined with parchment paper or a silicone mat. Bake for 10 – 12 minutes.

Allow to cool on the baking tray for 5 – 10 minutes before transferring them to a wire rack to cool completely.
The printable recipe card with the FULL list of ingredients and instructions can be found at the bottom of this post.
NOTE: For best results, I highly recommend using the gram measurements (with a digital scale), rather than the cup measurements.
Cup measurements are simply not accurate enough, and I cannot guarantee the best results if you use them.

These Peanut Butter M&M Cookies are:
- super quick and easy to make
- deliciously thick, soft, and chewy
- loaded with peanut butter flavour
- stuffed full of chocolate M&M’s
- simply the BEST peanut butter cookies!
How long will these peanut butter cookies last? These cookies will stay fresh, kept in an airtight container, at room temperature for up to 1 week.
Want freshly-baked cookies every time? Cookie dough balls can be kept in the fridge for up to 5 days, or frozen for up to 3 months. Bake straight from frozen.
If you try this recipe, let us know! Leave a comment, rate it, and don’t forget to tag me on Instagram and hashtag it #marshasbakingaddiction. I’d love to see!


Try these cookies next!
- Chocolate Crinkle Cookies
- Banana Breakfast Cookies
- Coffee Thumbprint Cookies
- Homemade Gingernut Cookies
- Condensed Milk Chocolate Chip Cookies
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Peanut Butter M&M Cookies

Deliciously thick, chewy, and soft peanut butter loaded cookies that are stuffed full of chocolate M&M's. These are the absolute BEST peanut butter cookies!
Ingredients
- 2 cups (250g) plain/all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 2 teaspoons cornflour/cornstarch
- 1/4 teaspoon salt
- 1/2 cup (115g) unsalted butter, melted
- 3/4 cup (150g) light brown sugar
- 1/4 cup (50g) caster/granulated sugar
- 1 large egg
- 2 teaspoons vanilla extract
- 1/2 cup (125g) smooth peanut butter
- 1 cup (170g) chocolate M&M's
Instructions
- Preheat the oven to 180C/350F/Gas 4. Line a baking tray with parchment paper or a silicone mat, and set aside.
- Whisk together the flour, baking powder, baking soda, cornflour, and salt. Set aside.
- In a separate large bowl, whisk together the melted butter and sugars until combined.
- Add the egg, vanilla, and peanut butter, and mix until combined.
- Add the dry ingredients, and mix until just combined. Fold in the M&M's.
- TIP: If you find the cookie dough too crumbly, add milk (1 tablespoon at a time) and mix until it comes together and is easier to manage.
- Roll the dough into 2-oz balls (or use a medium cookie scoop), and place onto the prepared baking tray. Bake for 10 - 12 minutes.
- Allow to cool on the baking tray for 5 - 10 minutes before transferring them to a wire rack to cool completely.
Notes
Cookies stay fresh, kept in an airtight container, at room temperature for up to 1 week.
Cookie dough balls can be kept in the fridge for up to 5 days, or frozen for up to 3 months. Bake straight from frozen.
Nutrition Information:
Yield:
18 cookiesServing Size:
1 cookieAmount Per Serving: Calories: 250Total Fat: 12gSaturated Fat: 6gTrans Fat: 0gUnsaturated Fat: 5gCholesterol: 27mgSodium: 141mgCarbohydrates: 31gFiber: 1gSugar: 18gProtein: 4g
Nutrition information isn’t always accurate.
Ree
Monday 1st of May 2023
I tried out your recipe and my goodness these cookies taste amazing!! I did press them down a bit before baking so they’d spread enough and they came out perfect! Definitely gonna make these again soon! ⭐️⭐️⭐️⭐️⭐️
Marsha
Monday 1st of May 2023
Hi Ree! I'm so glad you enjoyed them :)
Ruth
Saturday 11th of December 2021
I find that these don't settle in the oven. I had to press them down either before or after baking them.