Peanut Butter Cookies

A co-worker of mine made these peanut butter cookies that were wonderful.  They are the crispy kind but only have 4 ingredients!  Can you believe that!  I am posting this here to share with everyone and plan to make them soon!
 
1 cup peanut butter
1 cup sugar
1 tsp baking soda
1 egg
 
Mix together.  Use fork dipped in sugar to flatten.  Bake at 350 for 15 to 18 minutes