To make the crust, crush gluten free graham crackers in a blender or food processor, or place in a large zip-top bag and roll over with a rolling pin until crackers are finely chopped. If the pieces are too large, they won’t hold together in the crust, so make sure the crackers are crushed finely.
Stir together with sugar and melted butter or vegan butter, adding the extra one tablespoon if necessary to hold the crumbs together for the crust.
Press into the bottom and up the sides of a 9- or 10-inch pie pan. Place into cold oven while oven is preheating.
Set oven to preheat at 325° F.
Bring all cheesecake ingredients to room temperature, then blend together in a large food processor or stand mixer with whisk attachment. Process or beat until smooth, adding the citrus peel last.
Remove crust from the warmed oven and pour filling into the pan, filling only 2/3 full. If extra filling remains, pour into an oiled ramekin and bake separately.
Bake for 50 minutes, or until lightly browned and only slightly jiggly in the center. Turn the oven off, but leave the cheesecake in the oven for 1 hour more.
Remove to fully cool afterwards on a wire rack before refrigerating or topping.
Refrigerate until set and ready to serve.