In a small bowl combine flour, baking soda and salt. Give it a quick whisk (or stir) to combine dry ingredients together. Set aside.
In a separate mixing bowl combine shortening, peanut butter, and sugars. Using a mixer on medium speed mix ingredients together until combined. Add in egg, vanilla extract, and milk and continue mixing until combined. Batter will be smooth and thin.
Slowly add in dry ingredients and continue mixing until everything is well combined. Cookie dough will be thick and sticky.
Pour an extra amount of sugar onto a small plate.Using a tablespoon (the actual tablespoon you use to measure out ingredients) form cookie dough balls by rolling 2 tablespoons of cookie dough together with your hands to form a smooth circle. Roll formed cookie dough balls in sugar so that the surface is evenly coated. Placed sugar coated cookie dough balls onto a plate and let them chill in the refrigerator for about 30 minutes.
Preheat your oven to 375 degrees. Lightly grease a cookie sheet with non stick cooking spray or line with parchment paper. If you prefer, use a fork to press down the center of the cookie dough balls to form the traditional criss-cross pattern. This is optional.
Bake for 9-10 minutes. Cookies will be super soft but they will set as they cool. Allow cookies to cool for about 5 minutes before transferring them to a cooling rack. Serve once cooled.