Preheat oven to 425°F.
Place butter in an 8 or 10-inch cast iron (or other oven-safe) skillet and heat on the stove over medium heat until melted.
Add the cranberries and five spice in a single layer and let saute for a couple of minutes until fragrant and warmed through.
Meanwhile, add the eggs, milk, flour, sugar, vanilla, and salt to a blender and blend until frothy, about a minute.
Pour the batter over the fruit in the skillet and carefully transfer to the stove.
Bake until puffy and golden, about 20 minutes.
It will begin to collapse as soon as it comes out of the oven (don't worry about it).
Slice into wedges, drizzle with maple syrup or sprinkle with powdered sugar, and serve.
