From The Modern Family Cookbook 

¼ lb. dried prunes
1 package orange-flavored gelatin
1 cup boiling water
¾ cup cold water
2 oranges, peeled and sliced or diced

Soak prunes overnight in just enough cold water to cover; drain and remove stones. Cut in quarters, or smaller if prunes are quite large. Turn gelatin into mixing bowl, add boiling water, and stir until dissolved; add cold water (including water in which prunes were soaked) and stir in prunes. Cool until gelatin begins to congeal; then add oranges and chill until firm, either in a bowl or mold. Unmold. 5 servings.

My Note: You can’t get much more retro than jello molds! The prunes make it an extra treat.