Preheat oven to 350 degrees. Line baking sheet with parchment paper and set aside.
Mix cake mix, butter, eggs and flour until combined. Add M&M's and stir again.
Using a mini cookie scoop, measure out a bit of dough and roll into a ball. Then roll in the powdered sugar and place on cookie sheet.
Bake for 10-12 minutes, then remove from oven and give baking pan a few good pats against the counter to achieve the perfect crinkle (very important!). Let them sit on the baking sheet another 2 minutes or so and then transfer to wire rack.
Once completely cooled, dust with powdered sugar and enjoy!