Preheat oven to 350 degrees
Place parchment or Silpat over a cookie sheet.
Beat the sugar, brown sugar, and butter until fluffy.
Beat in the egg, vanilla, and peanut butter.
Add flour, baking soda and salt to the sugar mixture.
Blend well, scraping down the mixer bowl as needed.
Dough will be soft.
Shape teaspoonfuls of dough into round balls.
Roll in sugar and place on lined baking sheet.
Bake for 12-15 minutes or until firm.
Cool 5 minutes on the baking sheets then remove to a cooling rack to finish cooling.