In a small pot, melt the butter over medium-low heat
Pour the butter into the bowl and combine all the ingredients
Grease or spray a 23 cm springform pan
Fill the pan with the crumbly mixture and using a measuring cup press the mixture over the bottom
Cover and refrigerate while you make the filling
In the bowl of your electric mixer place the cream cheese, sugar and flour. Beat on medium speed until smooth.
Add the eggs, one at a time, beating well (about 30 seconds) after each addition.
Add the whipping cream, lemon zest and the vanilla extract and beat until incorporated (about 1 minute).
Remove the crust from the fridge and pour in the filling.
Bake at 177 C for 15 minutes. Then reduce the oven temperature to 120 degrees C and continue to bake for about another 1 1/2 hours or until firm and only the center of the cheesecake looks a little wet and wobbly.
In a medium bowl mix the sour cream, sugar and the vanilla.
pread the topping over the warm cheesecake and return to oven to bake for 15 more minutes.
Remove from the oven and let cool (this cheesecake tastes best after being refrigerated for about 12 hours).