Preheat oven to 325° and line a baking sheet with parchment paper.
In a large bowl, cream together the butter, sugar, egg and vanilla extract until smooth and creamy.
Add in flour, salt and baking soda. Mix until incorporated.
Add in milk and blend until it creates a ball of dough.
Next, add your red and green M&M’s, folding into the cookie dough.
Place cookie dough on a baking sheet using a cookie scoop about 1” apart.
Bake for 8-10 minutes, until the center has just set.
Allow to cool for 1-2 minutes until transferring to a cooling rack.
Allow to cool for 5-10 minutes more and enjoy!
For a pretty presentation, top each ball of dough with 3-4 M&M’s before baking!