Preheat the oven to 350°F (175°C) and line baking sheets with parchment paper or silicone baking mats.

In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

In a large mixing bowl, beat the softened butter with both sugars using an electric mixer on medium speed until the mixture is light and fluffy, about 2-3 minutes.

Add the vanilla extract and eggs, one at a time, mixing well after each addition.

Gradually incorporate the dry ingredients into the wet mixture, stirring until just combined.

Gently fold in the Christmas M&M's and chocolate chips.

Drop rounded tablespoons of dough onto the lined baking sheets, spacing each about 2 inches apart.

Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden and the centers remain slightly soft.

Let the cookies cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.