Marshmallow fluff is a sweet treat that's good on its own, but makes a wonderful fruit dip, ingredient in fudge, a cake filling or a topping.
1/3 c. water
3/4 c. granulated sugar
3/4 c. corn syrup
3 egg whites
1/4 t. cream of tartar
1 1/2 t. vanilla extract
Add the water, sugar, and corn syrup to a small saucepan; cook over medium heat until all the sugar dissolves and the mixture reaches 240 degrees F on a candy thermometer.
Wipe down the bowl of a stand mixer and the whisk attachment with white vinegar or lemon juice to eliminate any grease.
Add the egg whites and cream of tartar to the cleaned bowl; whisk on medium speed until soft peaks form, about 2 minutes.
Once the sugar mixture reaches 240 degrees F, remove it from the heat.
Turn the mixer to low speed; slowly pour the sugar syrup into the egg whites. Once all the syrup has been added, increase the speed to medium-high; whip until stiff peaks form. Add in the vanilla; mix until combined.
Store in an airtight container for up to 2 weeks.
Makes 4 cups.