Preheat oven to 375 degrees F (190 degrees C). In a medium bowl, combine 1 cup flour, 1/4 cup sugar and 1/2 cup butter. Mix until crumbly and pat into the bottom of a 9 inch springform pan.
In a medium bowl, toss together the chopped rhubarb, 1/2 cup sugar and 1 tablespoon flour. Pour onto crust. Bake in preheated oven for 15 minutes. Remove from oven and set aside. Reduce oven temperature to 350 degrees F (175 degrees C).
In a large bowl, beat the cream cheese and 1/2 cup sugar until creamy. Beat in the eggs one at a time. Pour over hot rhubarb in the pan.
Bake in the preheated oven for 30 minutes, or until filling is set. Cover with sour cream topping while still hot.
To make the sour cream topping: In a small bowl, combine 1 cup sour cream, 2 tablespoons sugar and 1 teaspoon vanilla. Mix well and spread on top of cake.
