Whisk together flour, instant pudding mix (just the dry mix), baking soda, and salt then set aside.
In a large bowl with an electric mixer or in a stand mixer beat butter with brown sugar and sugar. Add in egg and vanilla extract and continue to beat until creamy and well combined.
Slowly mix in dry ingredients making sure to scrape down the sides of the bowl as needed. Mix until combined then fold in 3/4 cup of M&M candies and chocolate chips. Chill for 2-3 hours.
Preheat oven to 350 degrees F. Prepare a baking sheet with parchment paper.
Roll out balls of dough and place them on your prepared baking sheet. Top your cooking dough with your remaining M&M candies by pressing them into the tops of your cookies.
Bake for 8-10 minutes. Remove from the oven and allow to cool on the pan for at least 10 minutes.