1. Cream butter and sugar (brown and white sugar); add vanilla, egg, peanut butter and milk. Add flour and baking soda to mixture and stir again. Form small balls and roll them in the sugar that you set aside.
2. Place them onto cookie sheet and bake at 350 for about 5-7 minutes, then open oven and press a kiss to the center of each and bake about 2 more minutes. Remove from pan and let cool, and enjoy!