Place the sauce, sugar, and zest in a saucepan over high heat. Stir to dissolve the sugar and bring to a boil. Reduce heat to simmer and cook, stirring occasionally, for 10 minutes or until sugar is completely dissolved. Remove from heat.
Preheat oven to 350 degrees F. Place the brie in an 8-inch pie plate. Bake at 350 degrees F for 10 minutes or until the brie is soft to the touch. Remove the brie from the oven and top with the cranberry sauce and sprinkle with the chopped pistachios and orange zest. Serve immediately with crackers, pita chips, sliced baguette or crostini.