SERVES 10

generous 1/2 cup butter, plus extra for greasing

1 3/3 cups finely crushed graham crackers

1 tbsp granulated sugar

2 lb cream cheese

1 1/4 cup cups superfine sugar

2 tbsp all purpose flour

1 tsp vanilla extract

finely grated zest of 1 orange

finely grated zest of 1 lemon

3 eggs

2 egg yolks

1 1/4 cups heavy cream

Preheat the oven to 350F. Place a small saucepan over low heat, add the butter, and heat until it melts, then remove from the heat, stir in the crushed crackers and sugar, and mic thoroughly. Press the cracker mixture tightly into the bottom of a 9-inch/23-cm springform cake pan. Place in the oven and bake for 10 minutes. Remove from the oven and let cool on a wire rack…Increase the oven temperature to 400F. With an electric food mixer beat the cream cheese until creamy, then gradually add the sugar and flour and beat until smooth. Increase the speed and beat in the vanilla extrct, orange zest, and lemon zest, then beat in the eggs and egg yolks one at a time. Finally, beat in the cream. Scrape  any excess from the sides and beaters of the mixer into the mixture. It should be light and whippy-beat on a faster setting if you need to…Grease the sides of the cake pan and pour in the filling. Smooth the top, transfer to the preheated ove, and bake for 15 minutes, then reduce the temperature to 200F and bake for an additional 30 minutes. Turn off the oven and let the cheesecake stand in it for 2 hours to cool and set. Cover and rerigerate overnight.. Slide a knife around the edge of the cake, then unfasten the pan, cut the cheesecake into wedge-shape slices, and serve.