In a bowl, beat shortening and peanut butter with an electric mixer.
Add granulated sugar, brown sugar, baking powder, and baking soda.
Scrap down bowl as needed.
Add in eggs, milk, and vanilla.
Beat in flour.
Chill the dough for at least 30 min.
Preheat the oven to 350 F.
Scoop dough into balls with a #40 cookie scoop.
Roll dough into balls and roll in the colored sanding sugar.
Place the cookies 2 inches apart on an ungreased cookie sheet.
Bake for 14 min until the edges are firm and the bottoms are light brown.
Remove from the oven and press a chocolate kiss into the center of each cookie. Cool for 2 minutes and transfer to a wire rack and let cool completely.