Preheat Oven: Preheat the oven to 325°F (163°C).
Prepare the Crust: Crush graham crackers in a bag using a rolling pin. Combine the crumbs, sugar, cocoa, and melted butter in a small bowl. Press the mixture firmly into the bottom of a 9-inch springform pan.
Make the Cheesecake: Melt the chocolate chips using a double boiler over medium heat, stirring occasionally until smooth. Set aside. In a food processor, blend cream cheese until smooth. Add the sugars and cocoa powder, and pulse until well combined. Add eggs, heavy cream, and vanilla extract, mixing until smooth. Finally, add melted chocolate and pulse again until fully incorporated.
Bake the Cheesecake: Pour the cheesecake filling into the prepared crust. Place the springform pan in the oven and bake for 75-80 minutes, until the center is set but still slightly jiggly. Once done, cool the cheesecake in the pan on a wire rack. Once cooled, cover and refrigerate for 4-6 hours.
Prepare Ganache: Heat the cream and butter in a microwave-safe bowl until melted. Add broken chocolate pieces, letting them sit for 1 minute before stirring until smooth. Let the ganache cool to room temperature before pouring it over the chilled cheesecake.
Garnishing: Shave the remaining chocolate bar into curls and sprinkle them on top. Garnish with Reddi-Wip and a drizzle of chocolate syrup before serving.