In a bowl, mix together the graham cracker crumbs, light brown sugar, and unsweetened cocoa powder with melted butter. Press the mixture evenly into the bottom of a 9-inch springform pan
In a large bowl, beat the cream cheese, mascarpone, granulated sugar, salt, and vanilla extract until smooth. Add the eggs one at a time—mixing gently after each addition—to avoid too much air.
Wrap the base and sides of the springform pan with aluminum foil and placing it into a larger baking dish filled with about 1 inch of boiling water. Bake the cheesecake at 320°F for 65-75 minutes