Heat oven to 375℉. Line a cookie sheet with a silicone baking mat or parchment paper. Set aside.
Using an electric mixer, combine cookie mix, oil, water, and egg until dough comes together. Place sugar in a small bowl.
1 pouch Peanut Butter Cookie Mix (17.5 oz.), 3 tablespoons Vegetable Oil, 1 tablespoon Water, 1 large Egg, Granulated Sugar
Using a small cookie scoop, form cookie dough into 1-inch balls. Roll cookie balls in the sugar and place 2-inches apart on prepared cookie sheets.
Bake for 10 to 12 minutes or until a light golden brown color. Remove cookies from the oven and immediately press 1 Hershey kiss in the center of each cookie, being careful not to press too hard.
36 Milk Chocolate Hershey Kisses, unwrapped
Using a small cookie spatula, remove cookies from cookie sheets and place them on a wire cooling rack to cool completely.
Once the cookies are cool, decorate one cookie at a time with the green decorator icing by swirling a line around the Hershey Kiss to look like garland on a tree. Sprinkle some Christmas nonpareils over the icing for decorations.
Green Decorator Icing, Christmas Nonpareils