Step 1: Preheat your oven to 350°F (175°C). Prepare a 9-inch springform pan by wrapping the bottom and sides tightly with two layers of heavy-duty aluminum foil. This is for the water bath.
Step 2: In a medium bowl, combine the chocolate cookie crumbs and melted unsalted butter. Mix thoroughly until the crumbs are evenly moistened.
Step 3: Press the mixture firmly and evenly into the bottom of the prepared springform pan. Bake for 8-10 minutes, then remove and set aside to cool slightly.
Step 4: Reduce your oven temperature to 325°F (160°C).
Step 5: In a large mixing bowl, using an electric mixer on medium speed, beat the softened cream cheese until it is completely smooth and creamy, about 2-3 minutes. Scrape down the sides of the bowl frequently.
Step 6: Gradually add the granulated sugar to the cream cheese, beating on low to medium speed until just combined and smooth. Avoid overmixing.
Step 7: Beat in the room temperature sour cream, unsweetened cocoa powder, and vanilla extract until fully incorporated and the batter is a uniform chocolate color.
Step 8: Melt the semi-sweet chocolate chips gently (microwave or double boiler) and let them cool slightly. Slowly pour the cooled melted chocolate into the cream cheese mixture, beating on low speed only until just combined.
Step 9: Add the large eggs one at a time, beating on low speed only until each egg is just incorporated. Avoid over-beating the eggs.
Step 10: Pour the chocolate cheesecake filling over the cooled chocolate cookie crust in the springform pan. Gently tap the pan on the counter a few times to release any trapped air bubbles.
Step 11: Place the foil-wrapped springform pan into a larger roasting pan. Carefully pour hot (but not boiling) water into the roasting pan until it comes about halfway up the sides of the springform pan.
Step 12: Carefully transfer the entire roasting pan with the cheesecake to the preheated 325°F (160°C) oven. Bake for 60-75 minutes, or until the edges are set and the center jiggles only slightly.
Step 13: Turn off the oven, crack the door open a few inches, and leave the cheesecake in the water bath for another hour. This slow cooling prevents cracks.
Step 14: Remove the cheesecake from the oven and water bath. Gently remove the foil. Let it cool completely on a wire rack at room temperature (2-3 hours). Once cool, cover loosely with plastic wrap and refrigerate for at least 6 hours, or preferably overnight, to fully set.
Step 15: For the topping: In a medium heavy-bottomed saucepan, combine the evaporated milk, granulated sugar, egg yolks, and butter. Whisk constantly over medium-low heat until the mixture thickens to a pudding-like consistency and just begins to bubble (8-10 minutes). Do not boil vigorously.
Step 16: Remove the saucepan from the heat and stir in the vanilla extract, sweetened shredded coconut, and chopped pecans. Let the topping cool completely to room temperature, stirring occasionally to prevent a skin from forming.
Step 17: Once the cheesecake is thoroughly chilled and set, carefully run a thin, sharp knife around the edge of the pan before releasing the springform collar. Spoon the cooled coconut pecan topping evenly over the top of the cheesecake, spreading gently to the edges.
Step 18: Return the finished cheesecake to the refrigerator for at least 30 minutes to allow the topping to set slightly. Then, it’s ready to slice and serve!