Preheat the oven to 350 degrees F
For the crust: Roughly break up the graham crackers and put them in a food processor with the cocoa powder. Process until finely ground. Slowly pour the melted butter into the processor while the motor is running. Press this mixture into the base of your prepared cake pan, using the ball of your hand or a spoon to flatten. Refrigerate the crust while you make the cheesecake filling.
For the filling: Using an electric stand mixer fitted with the paddle attachment or handheld mixer, mix the cream cheese, sugar and vanilla extract on slow speed until you get a very smooth, thick mixture. Add one egg at a time; ensuring each one is incorporated well before adding the next egg. Scrape any unmixed ingredients from the side of the bowl as needed. The mixture should be smooth and creamy. You can turn up the mixer to a higher speed at the end to make the mix a little lighter and fluffier but be careful not to over mix or the cheese will split.
Melt the chocolate using a double boiler until melted and smooth. Or if a microwave is your only option, melt the chocolate in increments of 30 seconds, whisking well after each :30 interval. Spoon a little of the cream cheese mixture into the melted chocolate, stir to mix then add a little more. This will even out the temperatures of the two mixtures. Eventually you can stir all the cream cheese mixture into the chocolate mixture until well combined and smooth.
Spoon the mixture onto the cold crust. If attempting the water bath, line the outside of the cake pan with a good layer of cling wrap and then another layer of strong foil over that to protect from the water bath. Put the cake pan inside a deep baking tray and fill with water until it reaches two-thirds of the way up the cake tin. If NOT attempting the water bath, simply put your cake pan into the oven and bake for 40 -50 minutes, checking regularly after 40 minutes to ensure the cheesecake doesn’t burn.
Don’t overcook the cheesecake. It should be wobbly in the center. Leave to cool slightly in the cake pan, then cover and refrigerate overnight before serving.
When ready to serve, if decorating with the chocolate curls: microwave your chocolate for 10-15 seconds and simply use your vegetable peeler to shave and create chocolate curls. You can do this right over the cheesecake so the curls just land on top. Enjoy!