For crust: Position rack in center of oven; preheat to 350°F. Blend graham cracker crumbs, brown sugar, flour, and coarse salt in processor. Add melted butter and 2 tablespoons water; process until crumbs are evenly moistened. Transfer crumb mixture to 9-inch springform pan with 2 1/2-inch-high sides; press mixture firmly onto bottom and 1 3/4 inches up sides of pan. Bake crust until set, about 15 minutes. Cool crust in pan. DO AHEAD: Can be made 1 day ahead. Cover; store at room temperature.
For filling: Line sieve with 3 layers of cheesecloth; set over medium bowl. Place ricotta cheese in prepared sieve; wrap cheesecloth around ricotta and squeeze gently to remove excess liquid. Cover and chill overnight (additional liquid will drain from ricotta). Preheat oven to 325°F. Wrap 3 layers of foil around outside of springform pan with crust, covering completely. Using electric mixer, beat cream cheese in large bowl until smooth. Add drained ricotta cheese and beat until blended. Scrape in seeds from vanilla bean; beat until well blended (reserve bean for another use). Add sugar, orange peel, vanilla extract, and coarse salt; beat until smooth. Add eggs 1 at a time, beating until blended after each addition. Transfer filling to baked crust in pan. Place springform pan with cake in large roasting pan. Add enough hot water to roasting pan to come halfway up sides of springform pan. Bake until cheesecake is set around edges and center no longer moves when pan is gently shaken, about 1 hour 30 minutes. Transfer cheesecake to rack and cool in pan 1 hour. Chill cheesecake uncovered overnight.
Using small knife, cut around cake sides to loosen. Remove pan sides. Transfer cake to platter. Cut cake into wedges and serve with Caramel-Orange Sauce .
Per serving: 584.0 kcal calories, 48.5% calories from fat, 31.5 g fat, 17.2 g saturated fat, 163.0 mg cholesterol, 66.4 g carbohydrates, 1.4 g dietary fiber, 57.3 g total sugars, 65.0 g net carbohydrates, 10.8 g protein Nutritional analysis provided by Bon Appétit