Step 1

For the crust: Preheat the oven to 350°. Wrap the bottom and sides of a 9-inch round springform pan tightly with aluminum foil. Lightly grease the pan with nonstick cooking spray. Set aside.

Step 2

Place the graham crackers, pistachios, brown sugar, and salt in the bowl of a food processor. Process until finely ground, about 30 seconds. Drizzle the melted butter over top of the graham cracker mixture. Process until it is the texture of coarse sand. Transfer to the prepared pan. Using a measuring cup, press the crust into the bottom of the springform pan. Press firmly to pack and make an evenly thick crust. Bake until the crust is lightly browned and smells toasty, 12 to 14 minutes. Cool the crust completely, about 30 minutes.

Step 3

For the filling: Place the ricotta and cream cheese in the bowl of a food processor and puree until very smooth, about 30 seconds. Add the sugar, flour, eggs, orange zest, vanilla extract, and salt. Process until smooth, about 30 seconds, stopping the food processor as needed to scrape the sides.

Step 4

Pour the filling into the cooled crust. Place the springform pan in a roasting pan and pour boiling water into the roasting pan to come halfway up the sides of the springform pan. Bake at 350° until the cheesecake is mostly set with a slight jiggle in the center, 1 hour 20 minutes to 1 hour 30 minutes. Carefully remove the cheesecake from the water bath to a wire rack and let cool to room temperature, about 2 hours. Remove the aluminum foil from the pan and refrigerate the cheesecake until cold and set, at least 6 hours.

Step 5

Run a paring knife around the sides of the pan and remove the pan. Garnish the cheesecake with chocolate shavings and chopped pistachios, if you like.