In the bowl of a stand mixer fitted with a whisk attachment, mix together the gelatin, spices, and 1/2 cup cold water. Allow to sit and soften while you prepare the sugar mixture. 

In a medium-sized saucepan, mix together the remaining 1/2 cup cold water with the sugar, corn syrup, and molasses. Allow to cook on medium-high heat until soft-ball stage, 240 F. Avoid stirring the mixture. 

While the mixture cooks, lightly spray a 9x13 pan with cooking spray. Mix the cornstarch and powdered sugar together in a small bowl, then pour a few tablespoons into the cake pan. Shake and rotate to evenly coat the entire cake pan with a layer of the mixture. 

With the mixer running on low speed, slowly pour the sugar mixture into the gelatin mixture. Once all the syrup has been added, increase the mixture speed to high and continue to whip for about 10 minutes until mixture has paled and has tripled in volume. Add salt and vanilla extract and allow to mix until just combined. 

Working quickly, pour the mixture into the prepared cake pan. Lightly grease your hands and spread it evenly into the cake pan, taking care not to press too hard. Sprinkle more of the powdered sugar and cornstarch mixture onto the surface of the marshmallows. Dust the top with the remaining powdered sugar mixture and a little more cinnamon, if you'd like. Allow the marshmallows to set at room temperature for at least 4 hours to set up. Once they have set, revert the mixture onto a cutting board and cut into squares as big or small as you'd like. Keep in an airtight container. Enjoy!