Preheat the oven to 375°F. Line two baking sheets with silicone baking mats or parchment paper.
In a large bowl, using a mixer, cream together the butter and sugars for 1 minute. Add the eggs and vanilla and mix until combined.
Add the flour, baking soda and salt and stir mix just until combined. Fold in the chocolate chips and M&M’s.
Using a large cookie scoop or ice cream scoop (about 3 Tablespoons), scoop the cookie dough onto the baking sheet about 2 inches apart. Place extra M&M’s on the top of the cookies.
Bake for 8-10 minutes, or until the tops are light golden brown.
Allow cookies to cool on pan for 2 minutes, and then transfer to a wire cooling rack.