- Combine 1 1/2 cups sugar and water in a saucepan. Cook over medium heat until sugar is dissolved, about 2 to 3 minutes. Add cranberries and vanilla and stir until well coated. Work quickly here as cranberries can pop if left in simple syrup for too long.
- Use a slotted spoon and transfer to a wire rack over a baking sheet. Let dry for 1 hour.
- Work in batches and roll cranberries in remaining sugar. (If using orange zest, it goes in with sugar prior to this step.) Coat completely and let dry on rack for another hour or overnight.