Using a stand mixer or hand mixer, cream butter and sugars on medium high for 4 minutes, until they are nicely combined.
1 cup unsalted butter, ½ cup granulated sugar, 1 cup brown sugar
Add in eggs, egg yolk, and vanilla and mix for another 1-2 minutes until the mixture is light and fluffy. Make sure to scrape down the side of the bowl at least once.
2 large eggs, 1 large egg yolk, 1 ½ teaspoon vanilla extract
Add flour, baking soda, baking powder, and salt, then mix on medium low until combined.
2 ⅓ cups flour, ½ teaspoon baking soda, ¼ teaspoon baking powder, 1 ¼ teaspoon salt
Fold in the candies and sprinkles with a spatula.
2 cups red white and blue M&Ms, ¼ cup red white and blue sprinkles
Using a cookie scoop, place cookies on a parchment lined baking sheet. Cover and refrigerate for at least 30 minutes.*
After 30 minutes, preheat oven to 375° F and line a baking she with parchment paper, placing 9-12 cookies evenly spaced on the prepared baking sheet. Press in additional candies and sprinkles to the top if you want a prettier cookie.
Bake cookies for 12-14 minutes, until they are just starting to brown around the edges.
Remove from oven and allow cool for a minute, then transfer to a wire cooling rack to cool completely.