April 16, 2015
The cookies turn out to be soft, buttery, and are loaded with milk chocolate M&Ms and semi-sweet chocolate chips.
To the bowl of a stand mixer fitted with the paddle attachment (or large mixing bowl and electric mixer) combine the butter, sugars, egg, vanilla, and beat on medium-high speed until creamed and well combined, about 4 minutes.
Preheat oven to 350F, line a baking sheet with a Silpat or spray with cooking spray. Place dough mounds on baking sheet, spaced at least 2 inches apart (I bake 8 cookies per sheet) and bake for 11 minutes, or until edges have set and tops are just set, even if slightly undercooked, pale, and glossy in the center. Cookies firm up as they cool. Allow cookies to cool on baking sheet for about 10 minutes before serving. I let them cool on the baking sheet and don't use a rack.
Cookies will keep airtight at room temperature for up to 1 week or in the freezer for up to 6 months. Alternatively, unbaked cookie dough can be stored in an airtight container in the refrigerator for up to 5 days, so consider baking only as many cookies as desired and save the remaining dough to be baked in the future when desired.