3/4 cup unsalted butter or margarine, room temperature
1/2 cup brown sugar
1/2 cup granulated white sugar
1 large egg
1 tsp. vanilla extract
3/4 cup peanut butter - Either smooth or crunchy works, but I prefer to use smooth.
2 cups all purpose flour
1/2 tsp. baking soda
1/4 tsp. salt
Preheat oven to 350 degrees F and place rack in center of oven. Line two baking sheets with parchment paper.
In a large bowl, cream together the butter and sugars with an electric mixer, until light and fluffy. Beat in the peanut butter. (Note: If you lightly coat your measuring cup with oil before measuring your peanut butter then it will slide out of the cup easier and you won't have to scrape it all out). Add the egg and vanilla extract and beat to combine.
In a separate bowl whisk together the flour, baking soda, and salt. Add the dry ingredients to the peanut butter mixture and beat until incorporated. If the dough is too soft to form into balls, cover with plastic wrap and place in the refrigerator for about an hour or until firm.
Roll the dough into 1 inch balls. Transfer the balls of dough to the prepared baking sheet, placing about 2 inches apart. Then, using the prongs of a fork, gently press down on the tops of the balls to make a crisscross pattern. Bake the cookies for about 10 to 12 minutes, or until the cookies are lightly browned around the edges. These cookies are nice and chewy, but if you prefer a hard, crunchy peanut butter cookie then just add an extra 2-4 minutes onto the baking time. Remove from oven and place on a wire rack to cool.
These are great cookies to mail because they keep fresh for quite a while and aren't very fragile. You can store them in the freezer so that they'll keep longer.
*Recipe from Joy of Baking