3/4 cup peanut butter
2/3 cup brown sugar, packed
1 large egg
1 teaspoon vanilla extract
1/2 teaspoon baking soda
1/4 teaspoon salt
4 ounces semi-sweet chocolate, coarsely chopped
Preheat oven to 350 degrees F (180 degrees C).
In a medium mixing bowl, mix together the peanut butter, brown sugar, egg, and vanilla until uniform. Stir in the baking soda and salt. Fold in the coarsely chopped chocolate.
Drop cookies by the tablespoon onto a baking sheet and bake for 8-10 minutes. Cool on the baking sheet for several minutes before moving to a cooling rack to cool completely (the cookies will be fragile and need to set-up before they can be moved).
I got the recipe here.