These gluten-free M&M oatmeal cookies are super fun! They're sweet and chocolatey with a light cinnamon brown sugar flavor with a great chew from the oats and crunch from the sprinkles and M&Ms! I use mini M&Ms and star sprinkles in addition to mini chocolate chips in this recipe to make them fun. Use seasonal M&Ms and different colored sprinkles to make these festive for any holiday! You can also leave all of those out and make plain oatmeal cookies with this recipe. Or, you can leave them out and add in chopped nuts and raisins for a more traditional oatmeal cookie.
To be sure that these cookies are gluten-free its very important that you use certified gluten-free oats and oat flour. It's very common for oats to be contaminated with gluten.
You want all of your wet ingredients to be room temperature for this recipe. But, if you’re anything like me you’re terrible at planning ahead. So, I have some tips for getting them not cold fast. For the egg: get a small cup and put your egg in it. Fill your cup with warm water (not hot! don’t cook that egg). Let it sit for about 10 minutes and bam, your egg isn’t cold anymore! For the butter: measure the amount you need and place in a microwave-safe bowl. Microwave it 10 seconds at a time at 40% power until it’s soft. There, now you can’t make these almost as soon as you find this recipe!
These gluten-free M&M oatmeal cookies are quite easy to make and taste just like a regular oatmeal cookie. Oatmeal cookies are my second favorite cookie, right after chocolate chip. They're perfect for putting in your kid's lunch box or as an afterschool snack. Or just eat them all yourself. If they want cookies they can get a job. Anyway, these aren't terribly healthy from all of the butter and sugar. But, they still contain about 2 grams of fiber per cookie from the oats. Oats themselves are very good for you, read more about them here:
https://bit.ly/31vvd3P
Well, you're set for a kid friendly dessert but what about dinner? How about chicken nuggets?
https://bit.ly/3fEZX7y 
Add the butter and brown sugar to a large bowl and mix well with a spoon or rubber spatula.
Add the egg to the bowl and mix well.
Add the rest of the ingredients except the chocolate chips, M&Ms, and sprinkles (or whatever other mix-ins you're using) and mix well. 
Now, add the mix-ins and mix. I like to use my hands for this part because the dough is hard to mix at this point.
Spoon the dough onto the cookie sheet, about 2 1/2 to 3 tablespoons worth. Don't press out the dough!
Place in the oven and bake for about 15 minutes or until they're just starting to brown around the edges.
Fully cool before wrapping them up. Enjoy!