Preheat oven to 350°F.

Using a food processor or mini-chopper, pulse the ladyfingers until finely ground.

In a medium bowl, combine the ladyfinger crumbs, melted butter and rum; stir until well combined.

Lightly butter or grease a 9” springform pan. Line the bottom of the pan with a circle of parchment paper. Press the crust mixture evenly into the bottom of the pan. (Tip: A flat-bottomed glass helps pack the crust mixture down evenly.)

Bake crust at 350°F for 6 minutes. Remove pan from oven and let cool.

Reduce oven temperature to 325°F.

Using an electric mixer, cream together the cream cheese, mascarpone and sugar until very smooth (~3 minutes on medium speed).

Add flour and espresso powder; mix until well combined.

Whisk the eggs and egg yolks together and add to the bowl in 2 additions, mixing fully after each addition.

Add the sour cream and vanilla; mix until well combined. (Tip: Use a spatula to scrape the sides and bottom of the bowl to ensure the filling is fully mixed.)

Pour the batter on top of the cooled crust.

Wrap the bottom of the pan with a piece of aluminum foil and place in a large baking pan. Fill pan with about ½”-¾” of water. Bake at 325° until center of cake is just barely set (about 80-90 minutes). (Tip: Pull the cheesecake out of the oven when there is about 1" ring of "looser" filling left in the center of the cake.)

Let cheesecake cool for 10-15 min and then wrap entire pan in plastic wrap; freeze overnight.

The next day, remove the cake from the freezer and release the springform pan. (Tip: Let cheesecake thaw slightly before releasing pan. Another option is to rotate the pan for several seconds over a gas burner to “melt” sides of the cheesecake…this makes it easy to release the pan.)

Transfer the cake to a serving platter and defrost in a refrigerator for 3-4 hours.

Prior to serving, whip the cream and powdered sugar together until stiff peaks form; set whipped cream aside.

Dust the cocoa powder of top of the cheesecake using a fine mesh sieve.

Using a piping bag with a large round tip, pipe whipped cream around edges of the cheesecake.

Using a small grater or vegetable peeler, grate semisweet chocolate on top of the cheesecake.