In a small bowl, cream the butter, confectioners' sugar and vanilla until light and fluffy. Gradually add flour and mix well. Stir in nuts and pineapple. Shape into 1-in. balls. Place 2 in. apart on ungreased baking sheets.
Bake at 350° for 14-16 minutes or until lightly browned. Remove to wire racks to cool completely. Roll cooled cookies in additional confectioners' sugar.