STEP 1

CHOCOLATE CRUST:
Preheat the oven to 350°F. In a saucepan over medium heat, melt the butter. Remove the butter from the heat. Add the chocolate cookie crumbs to the butter and stir until all the crumbs are coated. Press the cookie crumb mixture onto the bottom and sides of a 10-inch springform pan.

CHOCOLATE CHEESECAKE LAYER:
Prepare the cheesecake. Use an electric mixer to combine the cream cheese with the sugar, sour cream and vanilla, until creamy. Whisk the eggs in a small bowl and then blend them with the cream cheese mixture, just enough to incorporate the eggs.

In a small saucepan over low heat, melt the semisweet chocolate. Add the melted chocolate to the cheesecake mixture, stirring so that it is fully combined. Pour the cheesecake filling into the crust-lined pan and bake for about 12 minutes at 475°F, then turn the oven down to 350°F and bake for 50-60 more minutes or until the cheesecake top is lightly browned.

CHOCOLATE MOUSSE
In a small bowl, pour gelatin into the cold water and let it stand for a minute or two until it becomes soft, or “blooms.” Add boiling water and stir until gelatin is completely dissolved. Cool slightly. In a medium bowl, stir together sugar and cocoa; Add the whipping cream and vanilla. Using an electric mixer, beat the mixture while scraping the bottom of bowl occasionally. When the mixture has thickened, add the dissolved gelatin and beat until well blended. Cool the chocolate mousse in the refrigerator until you are ready to assemble the cake.

ASSEMBLE THE CHEESECAKE:
When the chocolate cheesecake has cooled, spread the chocolate mousse on top and sprinkle with shaved chocolate. Serve with a topping of whipped cream.