1. MELT chocolate & butterscotch morsels with sweetened condensed milk in top of double boiler over hot (not boiling) water. Stir occasionally till morsels melt and mixture begins to thicken. Remove from heat; add chopped walnuts and vanilla. Blend well. Chill for about 1 hour till mixture thickens. Line bottom of 9″ pie pan with a 12″ square of foil. Place cup walnut halves in bottom of pan, forming a 2″ wide flat ring.
2. SPOON chocolate mixture in small mounds on top of nuts to form ring. Decorate with remaining nuts. Add maraschino cherries if desired.
3. CHILL in the refrigerator until firm enough to slice. Cut into 1/2 inch slices. Makes about 36 slices.