Drain 1 jar (10-12 ounces) of maraschino cherries. Place the cherry juice in a measuring cup and add 3 ounces of white rum. You may use a tsp. of artificial rum flavoring and 3 additional ounces of cherry or other fruit juice if you don't wish to use rum. Marinate 12 cherries in the rum/cherry juice while you finish preparations.
In a large, cold mixing bowl, add 1 qt. of heavy cream, sugar or splenda and the vanilla. Whip on high for 2 minutes or until soft peaks form. Set aside.
In a medium mixing bowl, prepare one small package of instant vanilla or sugar free vanilla pudding with 2 cups of milk. Beat with electric mixer until thickened. Fold 1 cup of the whipped cream into the pudding mixture and set aside.
Place one layer of ladyfingers (split side up) in the bottom and standing up around the sides of a 8x8 inch baking pan or disposable pan. Drizzle 1/4 of the reserved cherry/rum juice over the ladyfingers evenly.
Top the ladyfingers with 1/3 of the yellow pudding mixture. Add a small layer of whipped cream to top the custard.
Add 2 more layers of the ladyfingers, cherry/rum juice and custard. Finish with final layer of ladyfingers, cherry/rum juice and remaining whipped cream in a decorative pattern. Top with the 12 marinated cherries. OPTIONAL: Sprinkle top with slivered, toasted almonds or shaved dark chocolate.
Cover and refrigerate overnight or at least 8 hours.