Peanut Butter Cup Surprise Monster Cookies

Peanut butter monster cookies with a Reese's peanut butter cup inside!! Recipe on

Welcome to recipe #6 in my Christmas cookie palooza. And let me tell ya, it’s a winner. Do I say that about every recipe I share? Dessert lover problems.

Sally's Cookie Palooza

Not only are we in the middle of a Christmas cookie celebration, today we’re also celebrating Sally’s Baking Addiction’s 3rd birthday. I can’t believe that I’ve been at this for three years! In the past three years I: got engaged, quit my job, started a business, moved 3 times (remember the flood?), wrote a cookbook, met readers, and got married. I started my blog two weeks after my grandmother passed away. She’s to whom my cookbook is dedicated and the main source of my inspiration.

And to all of you? I just want to say hey, thanks for reading my blog. =)

Peanut butter monster cookies with a Reese's peanut butter cup inside!! Recipe on

There are three reasons why I made today’s cookies:

1) My first post on Sally’s Baking Addiction includes peanut butter, so it seems only natural to celebrate my blog birthday with peanut butter the best flavor on earth.

2) Last year during my Christmas Cookie Palooza, I shared an absolutely ridiculous peanut butter stuffed cookie. Let’s make it a yearly tradition.

3) My peanut-butter-oatmeal-cookie-loving friend just turned 30 and I made desserts for her surprise party last weekend. We celebrated at a bar nearby with friends and family, lots of good food, wine, balloons, and a sugar overload. I made two batches of these, one pan of these, and a batch of today’s monster cookies. The cookies were the first dessert to disappear.

So there is always a reason (or three!!) to make peanut butter cup surprise monster cookies. I bet if you think real hard, you can find an excuse to make them too. Like, it being Thursday. And/or that you love M&Ms. And that peanut butter cups rule the world. And/or because your love for peanut butter cups runs deep.

Reese's Peanut Butter Cups for Cookies

The concept for these stuffed cookies is simple. Start by making the easiest peanut butter cookie dough. Guess what? There’s no mixer required. This oatmeal cookie dough can be mixed by hand. And it gets better: there is no dough chilling required either. The quicker you begin, the quicker you’ll be eating these.

This peanut butter cookie dough is a little different from my original monster cookies. It’s actually quite similar to my peanut butter cup oatmeal cookies. Instead of two sugars, however, I use all brown sugar in this particular cookie recipe. The reason for that? Softer oatmeal cookies. Brown sugar makes cookies extra soft because of all its moisture. Without the presence of granulated sugar, I noticed that these cookies didn’t spread as much. That’s one of granulated sugar’s jobs– to induce cookie spreading. I didn’t notice much of a taste difference using all brown sugar, but that’s only because there is so much peanut butter flavor. It overpowers everything else! A good thing, for sure.

To this peanut butter oatmeal cookie dough, add mini M&Ms. Regular size M&Ms are cool too. But I like the mini ones because you get more M&Ms in each monster bite. Traditional monster cookies include chocolate chips, but I didn’t add any to this recipe since there’s a chocolate treat hidden inside. Speaking of..

Reese's Peanut Butter Cup Monster Cookies - cookie dough

Stuffing them is easy. Grab some cookie dough, pat it down to flatten, place peanut butter cup on top, mold more cookie dough on top and around peanut butter cup.

Like I mention above, the cookie dough only spreads slightly in the oven. So, I suggest gently pressing down on the stuffed cookie dough balls to slightly flatten them (as best you can!) before baking. This gives them a little spreading “push.”

Peanut butter monster cookies with a Reese's peanut butter cup inside!! Recipe on

At first sight, they look like regular oatmeal M&M cookies… BUT it’s when you take that first bite when you notice all the peanut butter flavor and the hidden peanut butter cup surprise inside. These chewy, soft, overloaded oatmeal cookies will leave everyone begging for more. If heaven were a cookie, this would be it. ↓


Peanut Butter Cup Surprise Monster Cookies


  • 3/4 cup (95g) all-purpose flour (spoon & leveled)
  • 1/4 teaspoon salt
  • 1/2 teaspoon baking soda
  • 1/2 cup (115g) unsalted butter, melted
  • 1 cup (200g) packed light or dark brown sugar
  • 1 large egg, room temperature preferred
  • 1/2 cup (125g) creamy peanut butter (not natural style)
  • 2 teaspoons vanilla extract
  • 2 cups (160g) quick oats1
  • 1 and 1/4 cups mini or regular size M&Ms
  • 18 Reese's miniature peanut butter cups, unwrapped


  1. Preheat oven to 350°F (177°C). Line 2 large baking sheets with parchment paper or silicone baking mats. (Always recommended for cookies.) Set aside.
  2. Toss the flour, salt, and baking soda together in a large bowl. Set aside.
  3. In a medium bowl, whisk the melted butter and brown sugar together until no brown sugar lumps remain. Whisk in the egg, then the peanut butter until combined. Finally, whisk in the vanilla. Pour the wet ingredients into the dry ingredients and mix together with a large spoon or rubber spatula. The dough will be very soft and slick. Fold in the oats and the M&Ms. Allow the cookie dough to sit for 15 minutes-- the oats will absorb some moisture, making the dough easier to work with.
  4. You can use the photos above as visuals for this step. Take 1 Tablespoon of dough and slightly flatten out on the prepared baking sheet. Stick a peanut butter cup on top, as shown above. Top the peanut butter cup with 1.5 Tablespoons of cookie dough and seal down the sides so that the peanut butter cup is securely stuffed inside. You can pick it up and roll into a smooth ball if needed. Slightly flatten down the top as best you can (it can't be totally flat because of the peanut butter cup inside). Repeat with the rest of the dough and peanut butter cups.
  5. Bake the cookies for 12-13 minutes. The cookies will look very soft. They will continue to bake on the cookie sheet. Remove from the oven and lightly press down on each cookie to slightly flatten (if they didn't spread much in the oven). Allow to cool on the cookie sheet for 10 minutes before transferring to a wire rack to cool completely.

Make ahead tip: Cookies stay soft and fresh for 7 days at room temperature. Baked cookies can be frozen up to 3 months. You can freeze cookie dough balls by assembling as directed. Then chill in the refrigerator until firm and ready to pick up (you're doing this because the cookie dough is so sticky). Once firm, freeze dough balls in ziplock bags. Bake as directed for 1-2 extra minutes, do not thaw.

Recipe Notes:

  1. I do not recommend using old-fashioned style oats (aka whole oats) in this cookie recipe. They are the large-cut oats. You need quick oats, which are more finely ground (and smaller) whole oats. I often only buy old-fashioned (whole oats) from the store. So for this recipe, I simply pulse whole oats in a food processor a few times to cut them down to "quick oat" size.

Did you make a recipe?

Tag @sallysbakeblog on Instagram and hashtag it #sallysbakingaddiction.

© Sally’s Baking Addiction. All images & content are copyright protected. Please do not use my images without prior permission. If you want to republish this recipe, please re-write the recipe in your own words, or link back to this post for the recipe.

More peanut butter stuffed stuff: Peanut Butter Stuffed Brownies

Peanut Butter Stuffed Brownies by

Peanut butter monster cookies with a Reese's peanut butter cup inside!! Recipe on



  1. Ramona @ The Merchant Baker on December 11, 2014 at 3:14 pm

    Wow..3 years…time flies! I remember when you were celebrating your first! These cookies look like a hearty bunch of yum!

  2. Amy @ Amy's Healthy Baking on December 11, 2014 at 6:50 pm

    Happy blog birthday SBA!! 🙂 Sally, you’ve come SO far in just 3 short years. From your first blog post until now, your dedication to baking and honoring your grandmother with every cup of flour, tablespoon of peanut butter, and shower of sprinkles really shows. And your bright and beautiful photographs are just the frosting on the cupcakes! Or PB cup in the cookies… Regardless, you’re truly an inspiration and I’m so happy to have “met” you online! And I really want about 6 of these cookies right now. That’s all. 🙂

    • Sally on December 12, 2014 at 7:24 am

      And I really want to meet in real life and talk about cookies with you all day 🙂 xoxo Amy!

  3. Stephanie @ Girl Versus Dough on December 11, 2014 at 8:11 pm

    Happy blog birthday, Sally! Cookies with peanut butter in them are always a perfect way to celebrate. 🙂 I actually just told my mom we probably won’t be baking any cookies together this year, but I might have to change that now that I’ve laid on these bebes!

    • Stephanie @ Girl Versus Dough on December 11, 2014 at 8:12 pm

      That would be, “laid eyes on.” Oy. 😉

      • Sally on December 12, 2014 at 7:23 am

        Hahahahahahahahahaha I love you Stephanie.

  4. jenna @ just j.faye on December 11, 2014 at 10:11 pm

    These look so SO good! Congrats on the three year anniversary! I love your blog 🙂

  5. Shinee on December 11, 2014 at 10:43 pm

    Happy Birthday, SBA!!!
    These cookies look awesome. So excited to make these, not just because they look amazing, but also the whole batch would be just for me. Strangely, my in-laws are not a huge fan of peanut butter in cookies. I know! How is it even possible, right??

    • Sally on December 12, 2014 at 7:20 am

      Hahahaha I know people who don’t like PB in cookies too. I don’t understand (??) but to each his own!!

  6. Amy @ Thoroughly Nourished Life on December 12, 2014 at 1:05 am

    I freakin’ love these cookies too Sally!
    Happy 3 year blog birthday! The internet is a much more sparkly, sprinkly, peanut buttery, and awesome place because you are in it!
    So grateful that you share your life, your baking talents, and pictures of the gorgeous Jude with us every week 🙂
    You keep baking, we’ll keep loving!
    🙂 Amy

    • Sally on December 12, 2014 at 7:19 am

      Thanks Amy, you’re the sweetest. =)

  7. Anna (Hidden Ponies) on December 12, 2014 at 2:59 am

    Happy 3 years, Sally!! Your Grandma would be so very honoured and impressed by what she inspired 🙂

  8. Stacey @ Bake.Eat.Repeat. on December 12, 2014 at 11:42 am

    Happy blog birthday Sally! These cookies look absolutely insane! So much chocolate and peanut butter, it doesn’t get much better than that!

  9. Chelsey on December 12, 2014 at 11:47 am

    I made these last night!! Oh my, they were incredible!! A keeper for the recipe drawer!! Very easy to make too!!

    • Sally on December 12, 2014 at 1:34 pm

      Excellent! Thanks Chelsey.

  10. Abbie @ Needs Salt on December 13, 2014 at 2:43 pm

    Ahh, these cookies! They look pretty much perfect to me. (: And I can’t believe you’ve been blogging for 3 years!! Golly, has time flown or what. Keep up the awesome cookie awesomeness, girl!

  11. CakeSpy on December 14, 2014 at 7:52 pm

    Sometimes you need a cookie that is unpretentious, not uptight, and would NEVER EVER be paired with wine. This cookie is perfect for those moments.

  12. Jessica @ Jessica in the Kitchen on December 14, 2014 at 11:55 pm

    Wowza these are some loaded cookies! They are so thick and pretty and love that there is no dough chilling time. What’s even more amazing? Happy 3rd Anniversary for your blog!! I wish you many more great years blogging.

  13. JennyP on December 15, 2014 at 9:21 pm

    What a coincidence! I just made your biscoff oatmeal white chocolate cookies tonight, and I can see that this recipe base is similar. Can’t wait to try it – it is super easy and I love no mixing/chilling for weeknight baking. Btw, the biscoff cookies are amazing!!!

  14. Megan on December 16, 2014 at 4:07 pm

    Hi Sally!
    I was just wondering if it would be possible to freeze this cookie dough to bake at a later date, and how you would go about doing that?
    Thanks so much, these look amazing!

    • Sally on December 16, 2014 at 4:14 pm

      Absolutely! You may freeze cookie dough balls by assembling as directed. Then chill in the refrigerator until firm and ready to pick up (you’re doing this because the cookie dough is so sticky). Once firm, freeze dough balls in ziplock bags. Bake as directed (do not thaw) for 1-2 extra minutes.

  15. Melissa on December 18, 2014 at 12:06 am

    I just made these tonight, and my taste testers and I thought they were amazing!! I doubled the recipe to bring to my boyfriend’s family for the holidays and I think they will love them 🙂 Thanks for the recipe!

  16. Sarah on March 4, 2015 at 11:34 am

    Hello, Sally!!
    I really want to try this recipe, but I was wondering if there’s anything that can replace the oats…
    Thank you in advance and I hope you have a nice day!

  17. Alicia on June 18, 2015 at 6:27 pm

    Just made this cookies – SO good!! However, I did find that chilling for 30 mins made the dough wayyy easier to work with. My dough was very very sticky and my first batch spread more than I liked. Chilling the dough, and not pressing the cookies down, completely solved this problem!

    Thanks for another amazing recipe, Sally!!

  18. Sheila on January 5, 2016 at 1:32 pm

    I’ve made these cookies 3 times now and the only problem I’ve encountered is that I found the dough to be runny.  I’ve followed the recipe as is so not sure where the issue is.  BUT, this will not stop me at all from making these cookies.  They’re absolutely delicious and always a huge hit.  The last time I made them I actually crushed the mini cups and added them to the dough (because I just needed more chocolate peanut butter in every bite)!!  I’m so glad that I found you’re site.  Looking forward to making more of your yummy goodies!  

  19. Adrianna on December 4, 2016 at 7:41 pm

    The last time I made these, my family that doesn’t normally eat too many sweets ate a whole bunch. They were a total success. My sister asked me to make them for her party coming up… I’ll be doubling the recipe so that we have extras. =] So delicious!

  20. Kristin on January 14, 2017 at 6:34 pm

    I think these cookies are delicious! I followed the gram measurements, and didn’t even bother measuring with cups. I love it when I can just weigh something. I also love that I didn’t need to use my stand mixer. I actually made these cookies twice today. When my family discovered how good they were, I made a second batch to share with the kids I teach at my church. I chilled the dough the first time for about 30 minutes, and the second time for an hour. It made the dough a little easier to handle, but it’s still a little tricky to mold and shape around the PB cup. I kind of pressed the dough balls firmly together in between my hands until it was sealed all the way around… if that makes any sense. I DO think chilled dough helped make the dough less sticky. These are definitely a keeper. They’re yummy. They’re a good thickness. And I love that they have that hidden surprise inside. Thanks for the recipe, Sally!

  21. ShannaMade on March 9, 2017 at 1:53 pm

    Oh yum I love peanut butter and chocolate really want to try these!

  22. Lori on December 3, 2017 at 6:42 pm

    I can’t wait to try these, we are a peanut butter loving family. I was wondering, why is it suggested NOT to use “natural” peanut butter? Skippy’s Natural Creamy (“no need to stir”) is a staple in our house. Would that work?

    • Sally on December 4, 2017 at 8:27 am

      Hi Lori! Natural style PB is typically very oily and would result in overly crumbly cookies. But Skippy’s natural no-stir variety would be great here.



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