In a large bowl, whisk boiling water into gelatin mix, until powder is thoroughly dissolved. Let stand until cooled but not set, about half an hour.
Stir in grapes, drained pineapple, and canned cranberry sauce, until thoroughly combined. Add nuts if desired.
Pour into a deep 13x9-inch dish, cover, and refrigerate until set (at least 4 hours or overnight.) Makes 12-15 servings. Enjoy!