For the marshmallows: Sprinkle gelatin over 1/2 cup water in the bowl of a standing mixer with a whisk attached. Set aside for 5 minutes so the gelatin can soften and bloom.
Whisk together maple syrup and salt in a medium saucepan over medium heat. Gently simmer over medium heat until syrup reaches 240°F.
With mixer on medium speed, very slowly add hot syrup to gelatin and water in mixing bowl (it should take about 1 1/2 minutes to add all of the maple mixture). Turn mixer on high for 10 minutes until liquid has doubled and becomes light and fluffy.
To assemble: Spoon about 1/2 of marshmallow filling into a piping bag fitted with a large tip (or you can use a large ziploc bag and cut a hold in one corner). Pipe a large swirl of marshmallow filling onto each cracker, making sure to lift the tip off of the marshmallow filling to create the little dollop on top. Let sit for 30 minutes.
Melt chocolate over a double boiler (or in a heat proof bowl over a pot of boiling water). Stir in coconut oil until smooth. Place a marshmallow-topped cracker on a fork and hold over the bowl of melted chocolate. With your other hand, use a spoon to pour chocolate over the cracker and marshmallow. Place cookie on a cooling rack. Repeat with remaining ingredients.
For the remaining marshmallows: Spoon into a small oiled baking dish and let sit at room temperature overnight, uncovered. The next day, flip the marshmallows onto a greased cutting board. Cut marshmallows using a knife dipped in hot water, to prevent sticking (I also oiled my hands when handling the marshmallows to prevent sticking).