Melt 10 ounces bittersweet chocolate and set aside to cool.
Mix cream cheese and sugar until smooth, mix in cocoa powder
Add the eggs one at a time, mixing on low speed and do not overbeat it.
Add melted chocolate and mix on low speed to combine.
Pour the filling over the crust and smooth the top.
Bake the cheesecake until the center is set and the top looks dry (about 1 hour to 1 hour 10 minutes).
Cool on a wire rack for 5 minutes, then run a thin knife around the sides of the pan and set the cake in the refrigerator (uncovered), for at least 8 hours, or better overnight.