Preheat your oven to 325°F (163°C). In a mixing bowl, combine all-purpose flour, sugar, and salt. Cut in the unsalted butter using a pastry cutter until the mixture resembles coarse crumbs. Press this mixture evenly into a 9-inch pie pan to form a crust, ensuring the edges are slightly thicker. Set it aside while you prepare the filling.

In another bowl, combine the chopped fresh rhubarb, a sprinkle of sugar, and a bit of flour. Spoon this mixture over your unbaked crust, spreading it evenly. Bake in the preheated oven for 15 minutes.

Raise the oven temperature to 350°F (177°C). In a large mixing bowl, beat the cream cheese and sugar together until smooth. Add the eggs, one at a time, and mix until fully incorporated. Pour this cheesecake filling over the baked rhubarb layer.

In a small bowl, blend together the sour cream, sugar, and vanilla until smooth. Carefully spread this mixture over the cheesecake layer. Bake for an additional 15 minutes.

Remove the pie from the oven and let it cool on a wire rack for about 30 minutes. Refrigerate for at least 2 hours before serving.