Heat oven to 350º F. Spray a 12-cup bundt pan thoroughly with no stick cooking spray.
In a small bowl, place caramel topping. Stir in rum and pour topping mixture into prepared bundt pan
Place cake mix, pineapple juice, canola oil and 3 eggs into large mixing bowl and blend with electric mixer until moistened. Beat with mixer on medium speed for 2 minutes. Pour cake batter into cake pan over caramel topping.
To make the custard, place softened cream cheese cubes and cream of coconut into a food processor bowl fitted with a metal blade; process for about 1 minute. Add condensed and evaporated milks into a food processor bowl and process until smooth, pulsing at first so it doesn't splatter..
Add remaining 3 eggs, one at a time, and and just process until smooth. Spoon cream cheese mixture over top of cake batter.
Spray a sheet of heavy duty aluminum foil with no stick cooking spray and cover the pan TIGHTLY with the foil - important! (or use non-stick foil)
Place the covered bundt pan into a larger pan with at least 2-inch sides and place on oven rack. Pour very hot water (heated to just below boiling) around bundt pan about half way up the bundt pan for a bain marie.
Bake in 350º oven for 1 1/2 hours. Remove bundt cake from pan of water and allow to cool for 10 minutes. Remove the aluminum foil and invert cake onto a large platter. Cool completely at room temperature.
To garnish, sprinkle toasted coconut over top of . cake. Decorate with pineapple chunks and maraschino cherries, alternating them around top of cake. Refrigerate until thoroughly chilled.