This is another recipe originally from Sally’s Baking Addiction. If you can’t find mini red and green m&m’s (I couldn’t when I made them) just use regular size red & green m&m’s.
Preheat oven to 350. Line two baking sheets with parchment paper and set aside. Combine flour, baking soda, and salt together; set aside. In the large bow] of a stand mixer beat the butter and both sugars together until smooth and creamy; about 2 minutes. Add the egg and vanilla and beat on high until combined, about 1 minute. Add the dry ingredients and mix on low until combined. Stir in M&Ms.
Roll dough into very tiny balls, about 1 teaspoon each. Bake for 7-8 minutes until edges are lightly browned. Press a couple extra M&Ms into the tops of the cookies while still warm (just to make them look pretty). Allow cookies to cool 5 minutes on the baking sheets before transferring to a wire rack to cool completely.
Makes approximately 85 cookies.