Preheat oven to 325°.
Spray a 9-inch springform pan with non-stick spray. Set aside.
In a small bowl, mix together graham crumbs and sugar. Add butter. Stir until well blended. Press crumb mixture firmly over bottom and part way up sides of springform pan. Bake just until edges feel firm and dry, about 10 – 15 minutes. Be careful not to over bake. Set aside to cool. Reduce oven to 300°.
In blender, process cottage cheese and sour cream until smooth (about 1 minute). Add sugar, flour, eggs, and vanilla and process again until well blended.
Pour filling into pie crust and bake about 1 hour and 15 minutes, or until edges are dry to touch and center jiggles only slightly when pan is shaken. Remove from oven and cool completely. Cover and refrigerate for at least 5 hours before serving. Run a knife along inside edge of pan and remove sides. Serve with rhubarb topping.
Soak rhubarb in 1 gallon cold water for 20 minutes. Drain, pat dry with paper towels, and cut rhubarb crosswise into slices 1/2-inch thick.
Bring orange juice, orange zest, 3/4 cup sugar, and salt to boil in medium nonreactive saucepan over medium-high heat. Add rhubarb and return to boil, then reduce heat to medium-low and simmer, stirring only 2 or 3 times (frequent stirring causes rhubarb to become mushy), until rhubarb begins to break down and is tender, 7 to 10 minutes. Transfer rhubarb to nonreactive bowl, cool to room temperature, then cover with plastic and refrigerate until cold, at least 1 hour or up to 24.