In a non reactive, nonstick saucepan, over medium heat, combine the cranberries, zest, 1/2 cup sugar, water, salt, and cinnamon. Bring the mixture to a boil and cook for 10 minutes. Dissolve 1 tablespoon cornstarch in the orange juice. Add the mixture to the cranberries and stir to blend. Simmer another 15 minutes until the mixture is thick. Remove from the heat and cool completely. Cover and refrigerate until chilled.
In a non-stick one quart saucepan, combine 3/4 cup sugar and 2 3/4 cup milk together. Bring the milk to boiling point and scald the milk. In a small mixing bowl, whisk the remaining milk, egg yolks, and remaining 1/4 cup cornstarch together. Whisk until smooth. Temper the egg yolk mixture into the scalded milk. Bring the mixture up to a boil and cook for about 3 minutes or until the mixture is thick, stirring constantly. Remove the pan from the heat and stir in the vanilla and butter. Pour the filling into the individual pastry shells. Cover each pie with plastic wrap and place in the refrigerator. Chill the pie completely, about 2 hours. Using an electric mixer, whip the egg whites until stiff with the remaining sugar. Spoon the cranberry mixture over each of the pies. Top each pie with the meringue. Place the pie in the oven and bake for about 4 to 6 minutes or until golden. Remove from the oven and cool.