In a mixing bowl, cream butter and sugars. Add eggs,one at a time, beating well after each addition. Beat in vanilla. Combine the flour, baking powder, and salt; gradually add to creamed mixture. Cover and refrigerate for 2 hours or until easy to handle. With floured hands shape a tablespoonful of dough around 42 candies, forming a rectangular cookies.
Place 2 inches apart on greased baking sheets. Bake at 375 for 10 to 12 minutes or until edges are golden brown. Remove to wire racks to cool. In a microwave or saucepan, melt the remaining candies; drizzle over cookies.