Preheat the oven to 325°F (160°C).
In a mixing bowl, combine the graham cracker crumbs, melted butter, and granulated sugar. Mix until well combined. Press the mixture firmly into the bottom of the springform pan to form the crust.
In another large bowl, beat the softened cream cheese with an electric mixer until smooth. Gradually add the granulated sugar and continue mixing until creamy.
Add the vanilla extract and mix well. Add the eggs one at a time, mixing until just combined after each addition.
Stir in the melted semi-sweet chocolate and sour cream until well incorporated.
Pour the cheesecake filling into the prepared crust, smoothing the top with a spatula.
Bake in the preheated oven for 60 minutes or until the edges are set but the center is still slightly jiggly. Remove from the oven and let it cool to room temperature.
While the cheesecake cools, prepare the topping. In a saucepan over medium heat, melt the butter and brown sugar together, stirring until smooth. Add the shredded coconut and chopped pecans, mixing until well combined.
Once the cheesecake is completely cooled, spread the topping mixture evenly over the top. Refrigerate for at least 4 hours, or overnight for best results.
Carefully remove the sides of the springform pan before slicing and serving.