Preheat oven to 375 degrees.
In a mixing bowl, combine the shortening and peanut butter.
Add 1/3 cup granulated sugar and 1/3 cup light brown sugar; beat until fluffy.
Add 1 egg, milk and vanilla extract. Mix well.
In a separate bowl, combine your dry ingredients. Mix together the flour, baking soda, and salt. Next, you will slowly mix this into your peanut butter mixture until everything is well blended.
Shape the dough into 1 inch balls. Then, roll them in granulated sugar. Place them on an ungreased cookie sheet and bake for 8-10 minutes or until they are lightly browned.
Once the cookies are fully baked, remove them from the oven and immediately press one chocolate kiss into the center of the cookie. They will slightly melt and adhere to the cookie as they cool.