Preheat oven to 350℉.

Crust

In a bowl, combine 200 grams melted butter, flour, and eggs.  Mix until a dough is formed.  Spread the dough on a cookie sheet and bake in preheated oven for 30 minutes. 

Remove from oven and let cool, this step can be made a few days head.  When cool, grind the cookies in a food processor until crumbly.  

Add the remaining 4 tablespoons melted butter and mix until a uniform mixture is created.  Press into 2 (11-inch) springform pans and set aside.  

Filling

In a large bowl whisk the cheese and sour cream together until smooth.  

Add powdered sugar and mix until fully incorporated. 

Add eggs and potato starch, lemon zest, and vanilla extract.  Mix well.  Pour into prepared 11-inch springform pans.   

Bake for 10 minutes at 340℉/170℃ and then reduce heat to 280℉/140℃ for 40 minutes.

Topping

In a bowl with whisk blend the sour cream and powdered sugar until smooth.  

Spread on to the cakes and bake for 7 minutes more at a 300℉/150℃.

Cool and store in fridge until ready to serve.