Mix with your hands in a medium bowl peanut butter,Egg,sugar,and vanilla extract until well mixed.Mixture will be a little sticky to the touch. Sprinkle in flour until coated enough to handle without being sticky. (May not use all the flour.)Roll into balls and place on cookie sheet. Squash down with a fork one was then cross the marks again. My kids like to sprinkle some sugar on them before they bake. Can make fun with different colored sugar.
Bake for 10-15 minutes or until golden brown. Let cook and repeat. You can also double or triple the ingredients.