Preheat your oven to 375 degress F. If baking as one large cookie, preheat your oven to 340 degrees F. Lightly spray a mini muffin tin with non-stick spray.
In a small bowl, whisk together the flour, baking soda, and salt.
With a stand or handheld mixer, cream the butter, both sugars, and vanilla together until creamy. About 2 minutes.
Scrape down the bottom and sides of the bowl. Add 1 egg and mix until incorporated.
Add the second egg and mix until incorporated. Scrape down the bottom and sides of the bowl.
Add the flour mixture and mix just until it starts to come together. You will still see some flour that’s not fully mixed in.
Add the 10 ounce package of mini M&M’s.
Mix again for 10 seconds. You don’t want to crush the M&M’s, you just want to incorporate them.
Scrape down the bottom and sides of the bowl to make sure everything is mixed in.
Scoop with a small cookie scoop or a heaping tablespoon into the mini muffin pan.
Bake for 9-10 minutes. You want to barely see color starting to form around the edges.
Remove from the oven and let cool in the pan for about 5 minutes. They will slightly sink in in the middle as they cool. This is good because that’s where you can put the filling of your choice!
Remove from the pan and let completely cool on a cooling rack. They should come out of the pan easily. I take a steak knife and place it between the pan and the cookie, tilt the knife slightly and the cookie will pop right up.
You can also bake this in a cake pan for a big cookie! If you’re doing it this way, bake at 340 degrees F for 24-28 minutes.