3 egg whites
1/2 tsp. vanilla
1/4 tsp. cream of tartar
6 tbsp. sugar

In small bowl beat egg whites, vanilla, and cream of tartar at medium speed of mixer about 1 minute or until soft peaks form. Gradually add sugar, 1 tablespoon at a time, beating at high speed about 4 minutes or until stiff peaks form and sugar is dissolved. Immediately spread on pie, sealing to edges to prevent shrinkage.