In a medium sized saucepan over medium heat, dissolve the sugar in the orange juice with the orange zest and pumpkin pie spice. This has to be what heaven smells like.

Stir in the cranberries and cook until the cranberries start to pop (about 10 minutes). Turn heat to low and add Grand Marnier, stir, and cook for another minute or so.

Remove from heat and place sauce in a bowl. Cranberry sauce will thicken as it cools.