Preheat oven to 350 degrees.In a large bowl, cream softened butter, white and brown sugar.
You can use a stand mixer or a handheld mixer. Mix on medium speed for about two minutes, until the mixture becomes incorporated and fluffy. Set bowl aside.
In a separate bowl, combine flour, baking powder and baking soda with a whisk.
Add egg and vanilla to bowl with butter and sugar mixture. Beat for a few minutes until combined.
Add the flour mixture to the bowl with the wet ingredients. Add a little at a time and mix with mixer until all the flour has been incorporated.
Add pastel colored M&M's and chocolate chips and mix by hand.
Line two cookie sheets with parchment paper. Place rounded tablespoons full of dough onto the parchment paper a few inches apart. You should be able to get 12 cookies on a cookie sheet.
Press 3 or 4 pastel M&M's onto the top of each cookie before putting them in the oven.
Bake cookies for 8-10 minutes or until the edges become crisp. You want to be sure not to overcook these M&M Easter Cookies. You want to take them out of the oven while the middles are still a little soft.
When the cookies come out of the oven, move to rack to cool after a few minutes.