1. To toast coconut: spread coconut on a rimmed baking sheet and place in the oven. Stir every 2 to 3 minutes for about 10 minutes or until the coconut is lightly browned.
2. Remove from oven.Crush or grind the whole cookies to make crumbs. Tip: process whole cookies in a food processor or small grinder.
3. Add the toasted coconut and chocolate to the food processor and continue processing until the mixture is finely ground.
4. Add the butter and water and mix until thoroughly mixed and mixture is crumbly.
5. Pour the cookie crumb mixture into the springform pan. Using the back of a large spoon or the flat bottom of a measuring cup or drinking glass, press the crumb mixture firmly and evenly across the bottom of the pan.
6. Place the pan on a baking sheet; bake 10 minutes.
7. Remove from oven and place on a wire cooling rack to cool.When cooled, wrap bottom and sides of pan in a double layer of heavy duty aluminum foil to prepare for the bain marie water bath. The foil is to prevent any water from seeping into the cheesecake through the pan seams.Reduce oven to 325 degrees F.In a large bowl, add the cream cheese and sugar; mix on medium low speed with an electric mixer until smooth and creamy, 1 to 2 minutes. Scrape the mixture off the paddle and scrape down the sides and bottom of the bowl with a rubber spatula so the mixture blends evenly and there are no lumps.
8. Add the rum, vanilla extract, coconut extract, and flour; continue beating on medium low speed until thoroughly combined, about 1 minute.
9. Add the eggs 2 at a time, beating until thoroughly combined, about 1 minute, scraping the bowl between additions. Tip: crack the eggs into a small bowl and whisk with a fork to thoroughly break up the egg before adding to the cheese mixture.
10. Add the cream of coconut and stir until well blended. Tip: Do not overbeat the cheesecake batter. Blend the ingredients quickly to add as few air bubbles as possible. The ingredients must be well blended, but excessive beating creates too many air pockets which can cause the cheesecake to puff up too much during baking, and then crack during the cooling process.
11. Let the filling rest about 5 minutes to allow air bubbles to rise to the surface.Meanwhile, bring a large pot of water to boil to use for the bain marie water bath.
12. Pour the cheesecake filling into the cookie crust.
13. Bake: Set the foil wrapped springform pan in a larger pan or roasting pan and transfer to the oven. Carefully pour boiling water into the roasting pan to come halfway up the sides of the springform pan, and close the oven door.
14. Bake 60 to 70 minutes. Tip: The Cheesecake is done when the edges are set but the center 2 to 3 inches are still a pool of liquid batter. The cake should look as though it has puffed a little and just barely beginning to brown. The center will still be soft and jiggly when the pan is lightly jarred or tapped with a spoon.
15. Remove from oven, place springform pan on a wire cooling rack to cool. Immediately run a thin knife around the edge of the pan, gently pressing into the side of the pan to avoid gouging the cake. This allows the cake to contract away from the sides of the pan as it cools, helping to prevent cracks.When cheesecake is completely cooled, cover the pan and refrigerate for 12 to 24 hours before serving. Try to avoid having the covering touch the top of the cheesecake as this may mar the surface.
16. Place the chopped bittersweet or semisweet and unsweetened chocolate in a medium bowl. Set aside.In a small heavy saucepan over medium low heat, heat the cream of coconut until it is hot and just beginning to steam.
17. Remove from heat and pour over the chocolate, stirring until the chocolate is completely melted.
18. Add rum and coconut extract, stirring until completely mixed.
19. Remove from heat and set aside to cool about 10 minutes or until starting to cool and thicken.
20. Pour over center of cheesecake; use a small offset spatula to spread the chocolate to the edges.Sprinkle toasted coconut around the outside edge of the topping.Refrigerate the cheesecake until the topping is set, 20 to 30 minutes.