This recipe is for cinnamon sugar popcorn. It requires popping popcorn, then melting butter with sugar, cinnamon, salt and vanilla to make a syrup. The syrup is drizzled over the popcorn and tossed to coat before baking in the oven for 10 minutes with the heat off for an additional 20 minutes. Baking the coated popcorn allows the flavors to blend for a tasty cinnamon sugar popcorn snack.