Peanut Butter Oatmeal Monster Cookies

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These monster cookies are loaded with peanut butter, whole oats, chocolate chips and M&M’s. So thick and chewy, these monster cookies are addictive and delicious. 

What are Monster Cookies?

Monster cookies typically include oats, peanut butter, chocolate chips and M&M’s. These are not your typical crunchy, dry oatmeal raisin cookies. Oh no, these monster cookies are soft, thick and chewy. Plus, they are basically health food because they have peanut butter and whole grain oats. At least that’s what I tell myself after I’ve eaten an entire batch.

It has taken me a while to post a monster cookie recipe because even though I’ve been making these for years, it took me some time to create the perfect recipe. For monster cookies, you want the perfect balance of the peanut butter and oats. Not too much like a peanut butter cookie and not too much like a true oatmeal cookie. 

The Perfect Monster Cookie

So what makes the perfect monster cookie? I’ve learned a few things after making 82,647 batches. 

• 1:2 flour to oats ratio – I found that a 1:2 flour to oats ratio seemed to work the best. This recipe calls for 1 cup of all purpose flour and 2 cups of whole grain oats. Too much flour produced a dry cookie, too little made them thin and fall apart. 
• Room temperature butter – Why do I try anything different? Room temperature butter worked the best. I tried melted butter and even though I chilled the dough overnight, the cookies spread too thin. 
• Whole grain oats – I tried quick oats, but I lost too much of the oatmeal texture. The whole grain oats made them chewier and really made these monster cookies the perfect texture. 
• Molasses – I made some spiced oatmeal cookies for Christmas a while back and the molasses gave them a great “bend.” Only a little bit was used in this recipe because the flavor can be quite strong and I didn’t want it to take over the flavor of the monster cookies. 
• Chilling time – A minimum of an hour chilling time worked best. You can also chill them overnight. Because of all the ingredients in the monster cookies, they really need some time in the fridge or as I tell my kids…the cookies have to take a nap.

How to Make Monster Cookies 

1. In a stand mixer or using a hand held mixer, cream together your butter and sugar.
2. Add the peanut butter, eggs, vanilla and molasses. Scrape down the sides of the bowl.
3. Add your dry ingredients (flour, baking soda and salt). Be sure not to over mix. 
4. Add your oats, chocolate chips and M&M’s. Only mix until they are incorporated or you risk breaking up the ingredients too much. You want to keep that chunky texture. 
5. Cover your bowl in plastic wrap and chill in the fridge for one hour. 
6. Pull your dough out of the fridge while you preheat the oven to 350°F (177°C). 
7. Line your baking sheets with parchment paper. Using an ice cream scooper, scoop balls of the dough onto the parchment paper. Then, gently press down the dough so it will spread evenly. 
8. Bake at 350°F (177°C) for 9-11 minutes. They will not look completely cooked, but they will continue to cook on the baking sheet. 
9. This is optional but I pushed a few extra M&M’s on the top of the cookie as soon as they got out of the oven. This did two things: 1) it helped the cookies to flatted out a bit more and 2) they just look prettier with more M&M’s. 

Monster cookies are hands down my favorite cookie. My oldest kid who doesn’t like oatmeal or peanut butter has been devouring them. I think because they perfect incorporate all these ingredients with subtle hints of each flavor. I also like that you can switch out ingredients. Love health bar? Add it. Switch out the M&M’s for Reese’s Pieces. Love peanuts? Use chunky peanut butter instead of smooth peanut butter. These cookies are so fun to make and you can really get creative with the mix of things in the cookies. 

If you like these cookies, check out: 

• Chocolate Chip Cookies
• Rolo Cookies
• Oatmeal Creme Pies