Boo-nilla shakes: melt chocolate chips and paint ghost faces on inside of glass. Let harden before you fill the glass with a vanilla shake. (OR: Draw quick ghost faces on our clear plastic cups and have milk at snack time.
Orange-o-lanterns! (No link, just wanted to remind myself of the idea). Cut the top of the orange, hollow out (be sure to not cut lining too thin or it'll melt your candy). Make faces for the oranges and fill up with goodies!