1 cup peanut butter (chunky or smooth)
1 cup sugar
1 egg

Mix these ingredients together and with a spoon make mounds on a cookie sheet.

Flatten with a fork in a criss-cross pattern. Bake in a 375°F oven for 10-12 minutes.

Let cool slightly and transfer on a rack. Let cool completely. 

Note: 1/2 cup of chocolate chips can be added, but in that case use less sugar.