Beat together all crust ingredients. Press batter into the bottom and half way up the sides of a 9 inch springform pan.
For the filling, beat cream cheese and 1 cup sugar. Add in eggs, 1 cup sour cream, zest of 3/4 of the lemon, and vanilla. Pour into crust.
Bake at 325 degrees for one hour. Turn off oven and leave cake inside for an additional 15 minutes.
In a small bowl, stir together remaining sour cream, remaining lemon zest, and 1 tablespoon sugar. Spread over cake. Return cake to oven and bake at 325 for another 15 minutes. Allow cake to cool completely before slicing and serving.