For the coating: Whisk the sugars together in a small bowl. Sprinkle half the mixture liberally over the bottom of a parchment-lined, 8˝ square pan., For the marshmallows: Place the water in the large bowl of a stand mixer and sprinkle the gelatin over it. Let the gelatin soak until softened and translucent, about 5 minutes. Stir if there are any dry spots., In a medium saucepan, mix the maple syrup, maple flavor, and salt. Put over medium heat and cook until the mixture reaches soft-ball stage (235°F to 240°F)., Pour the syrup into the bowl with the gelatin and beat with the whisk attachment for 12 to 15 minutes, until the mixture holds a stiff peak when you pull up the whisk., Immediately spread the mixture into the prepared pan, using a wet offset spatula to smooth the top. Sprinkle 2 tablespoons of the remaining coating mixture over the top., When the marshmallow has cooled and set, cut into squares and dredge the edges of each square in the remaining sugar mixture to coat., Store marshmallows in an airtight container in a cool, dry place for up to 10 days., Yield: 2 dozen 1 1/2" marshmallows