Place butter in an 8 1/2 inch round glass cake dish.
Heat on full power for 1 minute.
Add graham cracker crumbs, cinnamon and sugar.
Stir to combine.
Press cracker crumb mixture onto bottom and sides of dish.
Heat on roast for 3 minutes.
Allow to stand and cool.
Cream cream cheese until smooth in a large, heat-resistant, non-metallic bowl.
Add pumpkin.
Beat until smooth and well-blended.
Add flour, vanilla, lemon and orange rind.
Mix thoroughly.
Add eggs, one at a time, mixing well after each addition.
Add vanilla and beat mixture for two minutes.
Heat, uncovered, on simmer for 5 minutes.
Stir twice.
Pour filling into crust and heat on simmer for 8 to 9 minutes or until custard is puffed around edges and still slightly soft in the center.