In a large bowl of an electric mixer, add egg whites, corn syrup, and salt.
Using your electric mixer on high speed, mix for approximately 5 minutes or until the mixture is thick and volume has almost doubled.
Reduce your mixer to low speed, add powdered sugar and mix until well blended. Add vanilla extract, mixing just until well blended.
Your homemade marshmallow fluff/cream is now ready to use in your recipes. Use immediately, or refrigerate in a covered container for up to 2 weeks.
Makes a large quantity.
Homemade Marshmallow Fluff Recipe: https://whatscookingamerica.net/Candy/MarshmallowFluff.htm