Peanut Butter Cookies

1/2 cup butter
1/2 cup peanut butter
1/2 cup sugar
1/2 cup brown sugar
1 egg
1/2 teaspoon vanilla
1 1/4 cups sifted flour
3/4 teaspoon baking soda
1/4 teaspoon salt
Preheat oven to 375?. 
Mix first six ingredients. 
Add the rest of the ingredients. Mix well. 
Roll into balls and press down with a fork dipped in sugar or flour. 
Bake for 10-12 minutes on ungreased cookie sheet.