- Crunch up or grind crumbs in food processor or blender, or roll between waxed paper sheets.
- Thoroughly butter bottom and sides of 9 inch spring form pan
- Mix all ingredients together and press lightly against bottom and sides of pan
- Beat the cream cheese in a bowl ( Jo uses a Kitchen Aid mixer) until smooth; gradually add sugar and beat on medium speed until sugar dissolves, about 3 minutes.
- Add eggs one at a time, beating until just incorporated and scraping down side of mixing bowl after each addition (this keeps the cream cheese from lumping)
- Add the zest and Vanilla and Lemon Extract and beat until just incorporated.
- Remove the bowl from mixer and stir in by hand the heavy cream, sour cream and flour.
- Pour the batter into the pan.
To keep the crust from cracking, put a roasting pan filled with boiling water on the lower oven rack and put the cheesecake in the middle rack. This keeps the oven and the cheesecake moist)
- Bake until filling is set, but the center jiggles (about 1 hour)
- Turn oven off and leave door ajar for 1 more hour
- While baking, make the topping