1. In the bowl of an electric mixer fitted with the whisk attachment, beat the egg whites, vanilla and cream of tartar on medium speed until frothy (the mixture will have medium to large bubbles), 10 to 20 seconds.

2. Continue beating until soft peaks form (the whisk will leave soft folds in the whites), about 1 minute.

3. Increase the speed to high and add the sugar, 1 Tbs. at a time, beating in each addition before adding more.

4. Continue beating until stiff, glossy peaks form, about 4 minutes more. (When the whisk is lifted out of the bowl and inverted, the whites should hold their shape with a slight bend at the tip.)

Williams-Sonoma Test Kitchen