Beat 6 egg whites to soft peaks using a stand mixer or with a hand mixer. Start medium speed and then turn up to high speed.  This may take several minutes.

Heat water in a small pot on medium heat, whisk gelatin into hot water until dissolved, then whisk in powdered sugar, then salt. Bring the hot sugar syrup to a boil and then remove from heat, allow the mixture to cool a little bit, and add vanilla bean extract.

Slowly pour the gelatin sugar mixture mixture into the bowl of the stand mixer with the stiff egg whites and continue to beat for 30-60 seconds until light and fluffy stopping to scrap the side of the bowl with a spatula to make sure there are no lumps in the marshmallow mixture.

Pour the homemade marshmallow fluff into a 8x8 prepared pan, spread evenly with a spatula, and refrigerate covered for at least 4 hours until set.

Once the marshmallows have set, cut and serve. Homemade marshmallows do not store well at room temperature.  Store them in the fridge in an airtight container for up to a week.