In a large bowl, cream peanut butter and sugar until light and fluffy (about 4 minutes).

Beat in egg and vanilla.

Fold in chips, if desired.

Shape level tablespoonfuls into balls.

Place 2 inches apart on ungreased baking sheets; flatten with a fork in a criss-cross pattern.

Bake at 350° for 16-18 minutes or until set.

Remove from oven and 'dust' with sugar.

Add additional candies, if desired.

Cool for 5 minutes; remove to wire racks.