Milk Chocolate Mascarpone Cheesecake

This is yet another cake that we served at Jake and Alice's wedding in June.  This is the best cheesecake--made all the better by the mascarpone. 

Chocolate Crust:
1 cup chocolate wafer crumbs
1/4 cup granulated sugar
3 tablespoons unsalted butter, melted

Filling: 1 1/2 pounds cream cheese, at room temperature
3/4 cup granulated sugar
1/4 cup all-purpose flour
1 teaspoon vanilla extract
8 ounces mascarpone cheese, at room temperature
3 large eggs, at room temperature
1/2 cup sour cream
6 oz. Milk Chocolate, melted and very warm

 Make Crust: 1. Position rack in center of oven and preheat to 350ºF. Butter bottom and side of a 9-inch springform pan. Line bottom of pan with parchment paper round, cut to fit. 2. Place cookies in bowl of food processor and process until finely ground. Add sugar and cocoa and process to blend. Transfer crumbs to medium bowl and stir in melted butter. Press crumbs into bottom of prepared pan and bake for 5 minutes. 3. Place pan on wire rack and cool crust while you prepare filling.

Make Filling: 1. Place cream cheese in bowl of electric mixer fitted with paddle attachment; beat on medium speed about until very smooth, about 2 minutes, scraping down sides of bowl as necessary. Gradually add sugar and continue to beat for about 4 minutes, or until well blended. Reduce speed to low and mix in flour, vanilla, mascarpone cheese, eggs and sour cream until blended. Stir 1 cup of cheese mixture into warm melted chocolate. Stir this mixture into remaining cheese mixture until completely blended. 2. Pour batter into cooled crust and smooth top with an offset spatula. 3. Place pan in a large roasting pan. Place pan on rack in oven and pour enough hot water into roasting pan to come halfway up side of springform pan. Bake for 50-60 minutes, until center is set (but still jiggly) and edges are puffed. Run a paring knife around sides of pan to loosen cake. Cool cake completely on wire rack. Chill for at least 2 hours before removing springform pan side to serve.