2In a medium bowl, cream together the butter and confectioners' sugar until smooth. Mix in the egg, lime juice and lime zest. Mixture may appear curdled, but that's okay. Combine the flour, baking powder and salt; stir into the lime mixture until well blended. Drop batter by teaspoonfuls into the cornflake crumbs. Place cookies 2 inches apart onto ungreased cookie sheets.
3Bake for 12 to 15 minutes in the preheated oven, until edges are golden. Remove from cookie sheets to cool on wire racks.