Preheat oven to 375 degrees F.
In a large bowl or food processor, mix together sugars, peanut butter, butter, and egg.
Combine dry ingredients, then add to the sugar mixture and mix until combined.
Shape dough into 1 ¼ inch balls. Place balls on an ungreased cookie sheet, about 3-inches apart.
Flatten balls in crisscross pattern with a fork dipped into sugar.
Bake for 7-9 minutes. Cool 5 minutes and serve.