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 or your fingers until the mixture resembles coarse crumbs. Press this mixture evenly into a 9-inch pie pan, making sure the edges are slightly higher for a nice crust.

Place the crust in the preheated oven and bake for 15 minutes until it's set but not browned. Remove it from the oven and let it cool slightly.

In a large bowl, toss the chopped rhubarb with some sugar and a sprinkle of flour until evenly coated. Spread this mixture evenly over the cooled crust.

Bake the rhubarb layer at 325°F (163°C) for 15 minutes. Remove it from the oven and let it cool slightly.

In a medium bowl, beat the cream cheese and sugar together until smooth. Add the eggs one at a time, mixing well after each addition. Blend in the vanilla extract, then spread this creamy layer over the baked rhubarb.

Increase the oven temperature to 350°F (175°C) and bake for 25 minutes. Let it cool slightly after baking.

In a small bowl, mix the sour cream, sugar, and vanilla extract until smooth.

Spread the sour cream mixture evenly over the cooled cheesecake layer and return it to the oven for an additional 15 minutes. Remove it from the oven and let it cool.

Let the pie cool on the counter for about 30 minutes, then refrigerate for at least 2 hours before serving.