We begin pre-heating the oven to 375 degrees. We put the shortening and the peanut butter in our KitchenAid mixer and begin stirring it with the paddle attachment for about 30 seconds. We scrape down the sides of the bowl with a rubber spatula and go from speed 2 to speed 4. We blend for about a minute. We turn the mixer off and add a 1/3 cup of the white sugar, and all of the brown sugar,breaking up the brown sugar as we add it to the mixer. We turn the mixer to speed 4 and beat for a minute. We turn off, scrape down the sides and the paddle, and turn to speed 6 for about 30 seconds. The mixture is nice and fluffy. We turn the mixer off and add the egg, milk, and vanilla extract. We turn to speed 4 and beat for a minute. We scrape the sides and paddle again, and turn to speed 6 for 20 seconds. We turn the mixer off.
Over a large piece of parchment paper, we sift the flour, baking soda, and salt with our fine strainer. We carefully carry this mixture over to our mixer and turn to the stir speed. We slowly add half of the flour, place the rest of the flour in the parchment on the counter, and turn off the mixer to scrape down the sides. We turn the mixer back on to speed 2 and slowly add the rest of the flour. When the flour is just incorporated, we turn off the mixer and remove the paddle and bowl.
We have the rest of the white sugar in a bowl. We cover our cookie sheets with parchment and get out our small ice cream scoop to make 1 inch balls of dough. With our scoop, we scrape out a ball, put it in our hands, and roll it gently. We then roll it in the sugar and place it on the cookie sheet. We fit a dozen cookies on each sheet and bake them 2 sheets at a time. When we have a cookie sheet filled, we place it in our oven and bake for 10 minutes. Meanwhile, when we have another sheet filled, we place it in the oven on an upper shelf, carefully noting the time. Before a batch of cookies is done, we are sure to wash our hands since we will be handling the Kisses.
As soon as the cookies are lightly browned and crackling, we remove them from the oven and immediately press a Kiss into the center of each cookie. We adjust the other cookie sheet in the oven, changing shelves, and then move the Kiss cookies to a wire rack to cool completely. We continue until all the dough is used, yielding 57 cookies.