light brown sugar, packed
all purpose flour
Preheat oven to 350 degrees and line a cookie sheet with parchment paper. (Just my preference)
In a mixing bowl, cream butter, peanut butter, granulated sugar and brown sugar.
Add vanilla and egg; beat until light and fluffy.
Sift flour and salt over the creamed mixture and blend into other ingredients thoroughly.
Form into 1 inch balls and place on prepared cookie sheet.
Press down the balls with the tines of a fork.
Bake in preheated oven for about 12-14 minutes, or just until golden brown.
It is a good idea to check bottoms of cookies for doneness before entire baking time is finished. These cookies will harden as they cool, and you don't want to overbake them!