Combine first 3 ingredients, stirring well (dough will be sticky). Stir in chopped pecans, if desired. Dust hands with powdered sugar, and shape dough into 3/4-inch balls. Coat balls with powdered sugar, and place 2 inches apart on ungreased baking sheets.
Bake at 350° for 10 to 12 minutes or until done; remove to wire racks to cool.