Sourdough Peanut Butter Cookies

1 cup sourdough starter
1 cup peanut butter
1 cup butter
1 cup brown sugar
2 cups flour
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon vanilla extract
2 eggs
1/2 teaspoon salt

Mix peanut butter, butter, brown sugar and flour. Add butter and remaining ingredients; form into small balls and press down with fork. Bake at 350 degrees F for 12 to 15 minutes on ungreased cookie sheet.

Yields 36 cookies.