Next, you’re going to want to scoop and chill the cookie dough. Scoop and roll the cookie dough into 1.5 tbs-sized balls. Place them on the prepared cookie sheet. Cover the dough balls tightly with plastic wrap and chill it for at least 3 hours, and up to overnight.
Bake the cookies for 9-10 minutes. The cookies will look pretty soft in the middle, and that’s okay. Remove them from the oven and gently press the M&Ms into the warm cookies. Allow the cookies to cool on the cookie sheets for 5 minutes or so before removing them to a wire rack to finish cooling completely.