Combine the graham cracker crumbs, walnuts, coconut, cocoa powder, and sugar in a food processor and process until fine crumbs. Pulse in the vanilla and melted butter until moistened. Press into the bottom and a little up the sides of a 10 inch springform pan. Bake for 5 minutes. Remove from oven, but keep oven on.
Place a 9×13 baking dish on the bottom rack of your oven and fill with warm water.
For the Cheesecake:
In the bowl of your stand mixer, fitted with the paddle attachment, beat the cream cheese until light and fluffy. Add one egg at a time, beating in-between, and scrape down sides of bowl occasionally.
Add the sour cream, sugar, vanilla and vanilla custard powder. Mix until smooth. Pour onto the prepared crust. Bake on the rack above the pan filled with water for 1 hour.
Turn off the oven, crack it open slightly and leave in oven for 1-2 hours. Remove from oven and let come to room temperature completely. Cover with plastic wrap and place in fridge to chill for 2 hours. Fix any cracks, if necessary.
For the Ganache:
Place the chocolate chips in a bowl, set aside. Heat the cream in the microwave for 1 1/2 minutes, then pour on top of the chocolate chips. Let sit for 30 seconds, then whisk until smooth. Let cool slightly, then carefully pour on top of the cheesecake. Refrigerate again until set. Enjoy!