Place the egg whites, sugar and cream of tartar in a heat proof bowl. We prefer to use the metal bowl of our stand mixer.

Fill a pot smaller than your bowl with a couple inches of water and bring to a boil. Once boiling turn down to a simmer and set the metal bowl on the pot to create a double boiler. Continuously stir the mixture until the sugar has fully dissolved and the egg whites are warm (about 3 minutes).

Transfer the bowl to a stand mixer fitted with the whisk attachment and mix on high until the mixture holds stiff peaks (about 5-7 minutes).

Add the vanilla and mix untill combined.

Stir in the Rice Krispies