Line your baking pan with parchment paper, crumble paper up to make it stay in place before lining the pan.
In a large bowl (or your stand mixer's bowl) add 1/2 cup of water and sprinkle the gelatin over it, and let stand for 5 minutes. Gelatin will appear "wrinkled"
In a medium saucepan, add the maple syrup, other 1/2 cup of water and salt. Stir and add a thermometer to the edge of the pan.
Turn heat up to high and bring to a boil, then reduce to medium heat until the mixture is about 230F.
Pour your mixture into stand mixer bowl or medium sized bowl with gelatin mixture already in it, mix in slowly.
Add the vanilla extract and set the speed to medium-high with whisk attachment for about 8-10 minutes until the mixture looks fluffy like marshmallow fluff.
Add the marshmallow mixture to the prepared baking pan and place in the fridge for 4-6 hours or overnight.