Preheat the oven to 180C (350F). For the crust, fill a Ziplock bag with the cookies and using a rolling pin, crush the cookies into small crumbs. 

Combine the cookie crumbs with the melted butter and firmly press onto a greased springform pan (20cm, 8 inches). Wrap the bottom of the pan with aluminium foil.

With a hand mixer, cream together the cream cheese and sugar until smooth.

Add in the eggs and vanilla and beat just until combined.

In a separate bowl, whip the heavy cream until soft peaks form. Then add in the cornstarch and continue beating until stiff peaks form.

Gently fold the whipped cream into the batter with a spatula.

Pour the batter on top of the crust and bake the cheesecake for 55 minutes, until it is slightly jiggly in the center.*

Combine the sour cream and powdered sugar until smooth and spread onto the cheesecake. Bake for another 10 minutes. 

Let the cheesecake cool in the oven with the door slightly opened for 1 hour. Then let it cool completely on the kitchen counter until it reaches room temperature. Then chill in the fridge for at least 6 hours or over night. Serve slightly chilled.