Heat 2 cups of honey, 1/2 cup water, and 1 tsp. salt in a medium saucepan. Add 1 tsp. vanilla and 1/4 tsp. of ground nutmeg, if using. Turn the pan to medium heat. Stir occassionally.
Gently boil the honey mixture until a candy thermometer reaches 225F/107C degrees. The honey should bubble, froth, and turn a deeper caramel color.
Once temperature is reached, immediately remove from heat and bring it over to the mixer.
Turn the mixer on low/medium (use the whisk attachment) and slowly stir honey mixture into the bloomed gelatin. Drizzle the honey down the inside of the bowl at a slow, steady rate.*
Mix to incorporate, stopping to scrape down sides a few times.
Once honey and gelatin are mixed, put the collar on your mixing bowl (if you have one). If you don't, place a towel over the top of the bowl to prevent splashes.
Turn the mixer to high and watch for the honey syrup to change into marshmallow fluff. The color will lighten and the mixture will thicken. You'll know the marshmallow mixture is ready to put in the pan when it becomes semi-stiff - a little bit like beaten egg whites, but stickier. This can take anywhere from 8-20 minutes.
Spoon the marshmallow cream into your prepared dish with a greased scraper. Cover them lightly with parchment paper without allowing the paper to touch the marshmallows. Set in a cool, dry place.
For softer marshmallows, let them set up for 4-6 hours. For dryer marshmallows, let them set up for 8-24 hours.