Lightly grease or line loaf pan.

Gently whisk gelatin and cold water together in bowl of stand mixer until combined.

Allow gel to form by sitting mixture aside for 10 minutes.

Place hot water in small saucepan and bring to a slight boil.

Remove from heat and stir in vanilla and stevia (or other sweetener of choice).

Turn mixer on to low speed and slowly pour hot liquid down side of bowl into gelatin mixture.

Increase speed to medium-high and beat for 1-2 minutes.

Increase speed to high and continue to beat until mixture is fluffy and soft peaks just begin to form, about 10-14 minutes (or 6-10 minutes if using other sweetener) being VERY careful not to over-beat.

Use mixture immediately for Marshmallow Fluff or pour mixture into loaf pan, tap on countertop a few times to evenly distribute, then allow marshmallows to set, uncovered, for a few hours or overnight.

Cut into 18 squares using sharp knife.

Store in airtight container at room temp or in fridge.