Peanut Butter Cookie in a Cup

While I was working on the Chocolate Chip Cookie in a Cup recipe, I knew I wanted to make a peanut butter version. So here it is, fresh from the microwave, a Peanut Butter Cookie in a Cup. 

Start with one tablespoon of butter and one tablespoon of peanut butter. I used creamy, but chunky works too!

Heat together in the microwave for about 30 seconds to melt butter and soften peanut butter.

Add one tablespoon of packed dark brown sugar, one tablespoon of white granulated sugar, a tiny pinch of Kosher salt, and a splash of vanilla. Stir together.

Add one egg yolk.  Discard egg white, or save for another use, do no add egg white or the cookie will be puffy and cake like.

Stir in egg yolk.

Add three level tablespoons of all-purpose flour. 

Stir to combine.

This step is optional, but makes for yummy crunch texture! Use a measuring cup, or large spoon and a plastic storage bag to crush up a few peanuts.

Sprinkle peanuts on top of cookie dough.

Microwave cookie dough for about 45 seconds, depending on the strength of your microwave. Start checking for doneness at 35 seconds to be safe.

Enjoy the peanut buttery goodness with a glass of milk, or a scoop of vanilla ice cream! 

Peanut Butter Cookie in a Cup

created by Melissa at No. 2 Pencil

1 Tablespoon of Butter

1 Tablespoon of Peanut Butter

1 Tablespoon of firmly packed Dark Brown Sugar

1 Tablespoon of Granulated White Sugar

2-3 drops of Pure Vanilla Extract {a splash}

Small pinch of Kosher Salt

1 egg yolk

3 level Tablespoons of All-Purpose Flour

Crushed Peanuts for topping

Melt peanut butter and butter together in microwave for about 30 seconds. Add sugars, salt and vanilla and stir to combine. Add egg yolk and stir again. Add flour and give a final stir. Sprinkle peanuts on top and heat in microwave for around 45 seconds. Microwaves vary, so start checking for doneness at 35 seconds. Serve warm!

If you like this recipe, try my Sugar Cookie in a Cup and Chocolate Chip Cookie in a Cup.

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Thanks for reading!



  1. This is so cool! I just happen to love peanut butter cookies too., thanks YUM

  2. Wanted to let you know we blogged about this delicious cookie too! Thank you for sharing these.
    Love your blog 🙂

  3. So yummy! Thank you so much! 😀

  4. nice idea.. thanks for sharing...

  5. Mmmmm, I think I like this better than the chocolate chip version.

  6. I was inspired by your blog so I tried Oatmeal cookie
    1 Tablespoon of Butter
    1 Tablespoon of firmly packed Dark Brown Sugar
    1 Tablespoon of Granulated White Sugar
    2-3 drops of Pure Vanilla Extract {a splash}
    Small pinch of Kosher Salt
    1 egg yolk
    1 tsp of cinnamon
    2 tbs of instant oats
    1 1/2 tbs of flour
    It may need some tweaking, but was yummy. Thanks for the great idea

  7. nice idea.. thanks for sharing.

  8. I just tried this and it was very good. Could have used a little more peanut butter flavor (I LOVE peanut butter!) I substituted Splenda for Baking and Splenda Brown Sugar Blend for the sugars and it still turned out yummy!

  9. This is so much better than the chocolate chip. The less time you keep them in the better!

  10. Anonymous says:

    mmm yum ! just had this with greek yoghurt on top 😀

  11. i tried this and it was good. the texture was between a cake and a cookie. It took a bit longer in the microwave, maybe cuz I made two at once. Is there a recommended mug size for best results?

  12. I was looking on Pinterest for recipes for Pina Colada cupcakes. I instead found your recipe for Peanut Butter Cup-cookies (long story). I am in no way disappointed!

    I had to microwave a bit longer than suggested, and then flipped it out onto a plate since the bottom didn’t quite cook and the top was drying, but the flavour….wow!! I’ve been craving peanut butter cookies for weeks and this has totally hit the spot! I also made your Sugar Cookie in a cup the other night and it was definitely a winner ^_^ So definitely going to be sharing these!

  13. Well not sure what happened! I tried it twice and on both occasions it became hard the moment I stirred in the egg yolk. Please help me

  14. thanks for sharing.

  15. Yummm!! i’m eating mine right now! it is absolutely delicious! i have tried all the cookies in the mug things aand i love them! thanks so much for your awesome ideas!

  16. Oh My!!!!! I am sending this to every woman I know! ♥

  17. Anonymous says:

    Can i use margarine as a substitute to the butter?

  18. Hey, can the brown sugar be substituted with honey? If yes, by how much?
    Also, how can I measure out a tablespoon of butter exactly? Yours are such perfect blocks.

    Thank you so muuch for these recipes! They’ll make my life so much more easier. :))

    • I haven’t tried honey, but let us know if you do!

      I buy sticks of butter and just slice off a tablespoon amount, it’s marked on the outside of the butter wrapper. Thanks for checking in!

  19. Unfortunately mine didn’t turn out well, it was very dry except for the bottom which didn’t really cook! I guess I just need a different mug or something!

  20. Heather says:

    Mine didn’t fare so well. It was extremely dry! I think my microwave may be the culprit though. The heating element is starting to wear down and sparks when I microwave anything, so I had to zap in 10 second increments. Will try again though!

  21. Hi! Thanks for sharing this recipe. I tried it and because I love peanut butter and banana I didn’t use the tablespoon of white sugar and instead put 1/8 of a banana cut into little pieces in there at the end before microwaving. It was awesome!

  22. Yum. I think this is my favorite of all your “in a cup” recipes. Also, for folks who like peanut butter and chocolate together, I tried throwing some chocolate chips into this one and it worked REALLY well.

    One thing I’ve been wondering… do you need a whole egg yoke for these? Since a full batch of cookies would probably have less egg per individual cookie, I’ve been wondering if you might be able to split the yoke and use each half to make cookies in a mug for two.

  23. Mmm the texture turned out well but could have been a bit more peanut buttery! Will add a little more peanut butter next time! Thanks for this recipe! I definitely like it better than the chocolate chip recipe.

  24. So good but could use more peanut butter

  25. Added some oats and put it in a the bottom of a flat bowl I had, added some ice cream on top, and it was delicious!

  26. Cwhitsett says:

    oh my. Oh, My! OH MY!!! THIS is just fabulous!!!! Did I mention it’s delicious? Can a food recipe get more than five stars, because this is definitely deserving! Came out of my microwave PERFECT! OH. MY!!!

  27. As I sit here scooping every last little bit out of the mug, I think i can safely say that this was a success! I combined this with your chocolate chip recipe by adding 2 tablespoons of mini chocolate chips to the
    batter at the end..mmmmmm. 🙂 I just love the combination of peanut butter and chocolate together!

    Cooking Notes: I used Earth Balance instead of butter and it still worked out well. However, I think I over mixed and over cooked it a bit, so I will have to fix that next time. It was still amazing though, thanks for the recipe!!

  28. Delish! I added a snack size pack of reese pieces too mine! Gives it that extra peanut butter taste! It definitely put it over the top! Thanks for sharing this wonderful recipe! 🙂

  29. We’re out of brown sugar at the moment, so used regular sugar in place and it doesn’t taste right. But I’m sure with brown sugar in the right place though these would be awesome. ^_^

  30. I really enjoyed this recipe….it was simple and easy to makee…

  31. Jessica says:

    I substituted a 1/4 cup applesauce for the egg, and the cookie was quite tasty! I did have to microwave it for a lot longer (may be due to our old microwave). It didn’t seem like it was going to cook all the way, but it eventually started to. The butter knife wasn’t completely clean, but I was too impatient to wait :D. It had a little bit of an apple flavor. I didn’t mind though, as it lent a nice sweetness to the cookie. Thanks for the awesome recipe!

  32. Catikas says:

    I love this recipe! My 3 year old and I just enjoyed the best peanutbutter cookie in a cup ever. Thanks for posting this!

  33. I just tried this recipe and was really looking forward to it after reading all the good reviews. However, after 1:20 of microwaving the cookie, it was still gooey after the first 45 seconds, the cookie is extremely crumbly. It looked like the crumbled up cake toppings that some people put on top of cupcakes. I’ve checked and re-checked the recipe and I am pretty sure I followed everything exactly…do you have any idea what went wrong? I did use light brown sugar instead of dark brown; could that be it?

    • I think you should try taking it out and letting it rest after 45 seconds. The heat from the cup will continue to cook the cookie. Good luck!

    • This happened to me too! I just ate spoonfuls of crumbles (although very tasty crumbles). I used the ingredients as listed. I wonder what went wrong? Maybe because it was all natural peanut butter (no added oils)?

  34. Oh my, those look amazing. ! I could totally eat this for breakfast

  35. Courtney says:

    Just tried this recipe–it was easy and delicious! Will definitely make again! Thanks!!

  36. Cooked it too long, so it was crumbly like others had commented, but this was a first time deal! Tasted good, so I mixed the crumbs up with vanilla Greek yogurt, yum!! I will make this again, solves my craving for a cookie without having to make 2 dozen that would have shamefully eaten in a day.

  37. This was super good! I added a scoop of peanut butter on the top ( I❤️ peanut butter!) And it softened on top, it was amazing!!! Thx


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