Preheat oven to 350 degrees. Line two baking sheets with parchment paper, set aside.
In a large bowl, combine both sugars and melted butter and mix until smooth. Add egg, egg yolk, vanilla, peppermint extract (start with 1/4 tsp and add more from there - the stuff is extremely potent!) and green food coloring until desired color is achieved. Stir until completely combined. Pour in pudding mix, flour, baking soda and pinch of salt and stir until just incorporated. Don't over mix. Fold in Andes mint chips and chocolate chips (I reserve about 2 tbs of each to press into the tops of dough balls before baking) until evenly distributed.
You may chill your dough for 30 minutes for thicker cookies (chilling is best for hot days). If not chilling, roll dough into 2 rounded tablespoons of dough and place 1 1/2-2 inches apart on baking sheets. If you reserved chocolate chips or mint chips, press into the tops of cookie dough balls now. Bake cookies for 11-12 minutes. Cookies will be underdone but will set up when they cool and stay very soft. Allow them to cool on baking sheets for 7-10 minutes until able to be handled without breaking apart before transferring to wire racks to finish cooling.
Grinch Mint Chocolate Chip cookies will stay soft and fresh for up to one week stored in an airtight container.