In a small bowl combine the gelatin and cold water. Set aside.

In a large saucepan combine the egg yolks, sugar, and milk. Cook over medium heat, stirring constantly, until the mixture coats the back of a spoon.

Add the gelatin and stir until completely dissolved. Remove from heat and cool for 5 minutes

Meanwhile, beat the cream cheese and vanilla with an electric mixer until fluffy. Add in the lemon zest and mix well. Beat the egg yolk mixture in gradually.

In a medium bowl beat the egg whites until they are fluffy. Fold into the egg yolk mixture.

In a chilled bowl, beat the heavy cream until soft peaks form. Fold into the cheesecake.

Pour into the graham cracker crust and chill for at least 3 hours.

Before serving, top with fresh berries.