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Boooo! Halloween Monster Mash Cookies! Festive, easy, sweet, and gravely spooky! Homemade chocolate chip cookies, made with oats, pretzels pieces, plenty of chocolate chunks, spooky Halloween M&M’s, and crazy candy eyes. There’s nothing not to love about these sweet chocolate cookies with a little salty pretzel crunch. Each bite is slightly crisp on the edges but soft and gooey in the center with melted chocolate throughout.

Halloween Monster Mash Cookies | halfbakedharvest.com

Ahhh! I am so happy to share these! In all honesty, I’ve wanted to make these fun, super yummy cookies for months. Actually, since almost a year ago when I made my much loved Christmas Monster Cookies. It was then that I knew that Halloween Monster Cookies needed to follow.

I’m not sure which cookie I love more. Both are unique, special, and melt-in-your-mouth delicious.

I know, I’m such a dork, but nonetheless, I just love how fun Halloween can be!

I wanted to share them very early in the Halloween season. My hope is that you can bake them up for all of your Halloween needs. Parties, school functions, and even just as a fun cookie to bake on a random weekday. Whatever you bake them up for, they require almost no effort!

Halloween Monster Mash Cookies | halfbakedharvest.com

Spooky details

Start off by gathering all of your ingredients. You’ll need the basics: salted butter, dark and light brown sugar, flour, baking powder, baking soda, and salt – the usuals.

You’ll also need the stir-ins, they’re the most important element of these cookies. You’ll need old-fashioned oats, salted pretzel twists, semi-sweet or dark chocolate chunks, and candy eyes. Plus plenty of spooky Halloween M&M’s, which, of course, make these cookies.

Simply mix up the dough, bake each cookie off, and then enjoy!

Halloween Monster Mash Cookies | halfbakedharvest.com

We love to eat these cookies warm, just out of the oven. They’re just the right type of gooey delicious cookies to pull out, slightly cool, and indulge in.

One thing that’s important to note, is that these cookies do spread, so don’t stress on that. Because of this, they’re meant to have slightly crisp edges and perfectly soft gooey centers, just like in the photos. My favorite type of cookie. Everyone has really been loving these cookies, they’re definitely an Oslo favorite!

Halloween Monster Mash Cookies | halfbakedharvest.com

If you want a bit of a thicker cookie, simply omit the additional egg yolk and use only two eggs. As a result, this will give you a thicker cookie without as much spreading.

To get the M&M’s to really pop, I like to add in a few just before the cookies finish baking completely. This way each cookie has a bit of the festive M&M’s right on top.

Excited to see you all bake these up this month! What’s incredible about these cookies is just how easy they are. So have fun with them and enjoy every shamefully sinful spooky monster bite!

Halloween Monster Mash Cookies | halfbakedharvest.com

Looking for other Halloween cookies? Here are my favorites: 

“I put a Spell on You” Poison Apple Martini

Black Widow Peanut Butter Bars

Hocus Pocus Spellbook Brownies

Spooky Halloween Pretzels

BOO! Chocolate Peanut Butter Bars

Milk Chocolate Stuffed Jack-O’-Lantern Cookies

Black Cat Pumpkin Cupcakes

Roly Poly Pumpkin Cookies

Lastly, if you make these Halloween Monster Mash Cookies, be sure to leave a comment and/or give this recipe a rating! Above all, I love to hear from you guys and always do my best to respond to each and every comment. And of course, if you do make this recipe, don’t forget to tag me on Instagram! Looking through the photos of recipes you all have made is my favorite!

 

Halloween Monster Mash Cookies

Prep Time 20 minutes
Cook Time 15 minutes
Total Time 35 minutes
Servings: 20 cookies
Calories Per Serving: 311 kcal

Nutritional information is only an estimate. The accuracy of the nutritional information for any recipe on this site is not guaranteed.

Watch the How-To Reel

Ingredients

Instructions

  • 1. Preheat the oven to 350° F. Line a baking sheet with parchment paper.
    2. In a bowl, beat together the butter, brown sugar, and vanilla until combined. Beat in the eggs and 1 egg yolk, 1 at a time, until combined. Add the flour, baking soda, baking powder, and salt. Beat in the oats.
    3. Fold in 1 cup of the M&M's, the pretzels, and chocolate chips.
    4. Roll the dough into 1/4 cup size balls. Place 3 inches apart on the prepared baking sheet.
    5. Bake for 8 minutes, then rotate the pan and bake another 2 minutes. Pull the pan out and push the remaining M&M's and candy eyes into the cookies. Bake 2-3 minutes. Remove from the oven and let the cookies cool on the baking sheet. They will continue to cook slightly as they sit on the baking sheet.
    6. Eat warm or let cool and store in an airtight container for up to 4 days. 
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Halloween Monster Mash Cookies | halfbakedharvest.com
This post was originally published on October 4, 2022
4.69 from 114 votes (51 ratings without comment)

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Comments

    1. Hey Meghan,
      I would just skip them:) I hope this recipe turns out amazing for you, let me know if you have any other questions! xx

  1. 3 stars
    These taste fine, but they’re sooo flat and gooey that I just cannot get them to set. They turned out kind of a mess. My oven temp is correct and my leavening agents are fresh. I even tried refrigerating the dough, and that didn’t help. They taste good, but look very messy (which is sorta cute for Halloween, but wouldn’t work any other time!).

    1. Hi there,
      Thanks for giving the recipe a try and sharing your feedback! I do note “One thing that’s important to note, is that these cookies do spread, so don’t stress on that. Because of this, they’re meant to have slightly crisp edges and perfectly soft gooey centers, just like in the photos. If you want a bit of a thicker cookie, simply omit the additional egg yolk and use only two eggs. As a result, this will give you a thicker cookie without as much spreading.” I hope this helps for next time! xT

  2. Yummy! Just made a half batch and think they’re to “die” for 😉 cute touch w the eyeballs! My kids can’t wait to have in their lunch tomorrow!

    1. Hey Stacy,
      Awe love to hear this!! Thanks for making them and sharing your feedback!! Have a great Thursday! xTieghan

      1. 5 stars
        I love how this recipe came together so easily. They taste delicious and so festive for the Halloween season. Another big hit in my house. Thanks, Tieghan!

        1. Hi Julie,
          Happy Friday!! I am delighted to hear that this recipe turned out tasty for you, thanks a bunch for giving it a try!

  3. I followed this recipe to a T and my cookies are very dense balls and didn’t flatten. What did I do wrong?

    1. Hi Shona,
      Thanks for giving the cookies a try. Were all of your ingredients at room temp? Is it possible you over mix the dough? Have you tried tapping your baking sheet on the counter or gently flattening the dough with your hand? Let me know! xTieghan

    1. Hey Amanda,
      Sure, peanut M&M’s would be great! Let me know if you give the cookies a try, I hope you love this recipe! xT

    1. Hi Sherish Ali,
      For this recipe, I would recommend sticking with the old fashioned oats! Please let me know if you have any other questions! xTieghan

  4. 5 stars
    Can you use gluten free flour in place of the all purpose? Look these but my niece is gluten free. Thank you 🙂

    1. Hey Ashley,
      Yes, that will work well for you! I hope you love these cookies, please let me know if you give them a try! xTieghan

    1. Hey Jackie,
      Totally, that will work well for you! I hope you love this recipe, please let me know if you give it a try! xT

  5. 5 stars
    Just pulled these out of the oven. Wow! Just wow! My husband claims that these are the best cookies he’s had in a long time. I think he was wondering why I bought pretzels today because we’re both not pretzel fans. Now when I told him this was where the pretzels were in, he figured best pretzels he’d ever had!

    1. Hey Teresa,
      Happy Wednesday! I am thrilled to hear that this recipe was a winner, thanks a bunch for making it! xT

    1. Hi Lesley,
      I’ve not tested this, but if you omit the oats I would add 1/3 cup of flour. Let me know if you give the recipe a try! xTieghan

  6. These look great! I was also wondering about the eyes with eyelashes. I’ve checked Halloween M&Ms and they do not appear to have those.

  7. Can I use quick oats? I made the mistake of buying them instead of old-fashioned for my granola and would prefer to use them up before buying more… these look amazing! Thanks!

    1. Hi Alix,
      So sorry, you will definitely want to use old-fashioned oats for best results with these cookies:) Please let me know if you have any other questions! xx