Preheat the oven to 350ºF. Line a baking sheet with parchment paper.
In the bowl of a stand mixer fitted with the paddle attachment, beat shortening, butter, brown sugar, and granulated sugar together until creamy, 1-3 minutes.
Add the eggs and mix well.
Beat in peanut butter, milk, and vanilla extract.
In a large bowl, whisk together flour, baking soda, and salt.
Add the flour mixture to the butter mixture in about 3 parts, mixing just until incorporated.
Using your hands, roll dough into balls about 1 ½ inch in size, then roll the balls in extra sugar until completely coated.
Place dough balls 2 inches apart on the prepared baking sheet. Bake 10-12 minutes or until just starting to brown around the edges.
Remove the cookies from the oven and immediately press a Hershey’s kiss into the center of each cookie.
Allow to cool 5 minutes on the baking sheet before removing to a cooling rack. Allow to cool completely.
Repeat with any remaining dough.
Notes
Tips for customizing
Use all butter or all shortening depending on your preference
Use chocolate stars or mini peanut butter cups instead of kisses
Skip rolling the balls in sugar if you want to decrease your sugar consumption
Use all shortening and dairy free milk to make these dairy free
Half the recipe if you don’t need so many cookies (there is a button to make this easy in the recipe card!)
Roll the cookies in colored sugar for an extra festive look
Use a different flavor or kisses such as caramel or cherry