**Prepare the Crust:** Preheat your oven to 350°F (175°C). Combine chocolate cookie crumbs and melted butter in a bowl. Press the mixture into the bottom of a greased springform pan. Bake for 8-10 minutes, then set aside to cool.
**Make the Cheesecake Filling:** In a large bowl, beat cream cheese and sugar together until smooth. Add sour cream and melted chocolate, mixing until fully incorporated. Beat in eggs one at a time, followed by vanilla extract.
**Assemble and Bake:** Pour the filling over the cooled crust. Place the springform pan on a baking sheet and bake for 55-65 minutes, or until the edges are set and the center is slightly jiggly. Turn off the oven, crack the door open, and let the cheesecake cool in the oven for 1 hour.
**Chill the Cheesecake:** Remove from the oven and refrigerate for at least 4 hours or overnight.
**Prepare the Coconut-Pecan Topping:** In a saucepan over medium heat, combine butter, evaporated milk, sugar, and egg yolks. Cook, stirring constantly, until thickened, about 8-10 minutes. Remove from heat and stir in vanilla extract, coconut, and pecans. Let cool to room temperature.
**Top the Cheesecake:** Spread the cooled coconut-pecan mixture evenly over the chilled cheesecake.
**Serve:** Remove the sides of the springform pan, slice, and enjoy!