3 egg whites [110 grams]
3/4 cup [165 grams] granulated sugar
1 teaspoon vanilla extract
1/4 teaspoon cream of tartar
Pinch of salt
We need to make a double boiler so place a large bowl over a small pot with a bit of water in it. Place the pot with the bowl on the stove and turn the heat to medium low. In the bowl, add the egg whites and sugar. While whisking, heat the eggs whites and sugar until the mixture is thoroughly warmed up and the sugar is dissolved. Remove from the heat.
Place the egg whites and sugar along with the other ingredients into the bowl of a standing mixer. Turn to medium speed and beat until the mixture has doubled, turned smooth and glossy, and achieves stiff peaks. Spoon onto the cooled pie.