01 -
Set the oven to 350°F and prepare two baking pans by lining them with parchment paper.
02 -
Combine the flour, baking soda, baking powder, and salt. Give them a good stir.
03 -
Use a mixer to cream butter and both sugars until fluffy, around 1-2 minutes. Mix in the egg and vanilla until smooth.
04 -
Add the dry blend to the wet mix on a low setting until just blended. Stir in about a cup of M&M's gently.
05 -
Roll dough balls using 1½-2½ tablespoons. Add the leftover M&M's on top, then coat balls with sprinkles.
06 -
Bake right away for flatter cookies, or chill the dough for 15 minutes if you want fluffier results.
07 -
Pop them in the oven for 8-11 minutes. The edges should be set, but the center can be slightly gooey. Adjust shapes when hot, if needed.
08 -
Let the cookies cool completely on wire racks. They'll firm up during cooling.