Beat egg whites in large bowl with electric mixer on medium speed until frothy. (If using a freestanding mixer, use wire whisk attachment.) Add cream of tartar; beat until soft peaks form. Increase speed to medium-high. Add sugar, 1 tablespoon at a time, beating until sugar is dissolved and stiff peaks form. Beat in extract. Gently stir in chips, if desired.
Drop by rounded measuring teaspoonfuls about 1 inch apart onto 2 large foil-lined baking sheets sprayed with no stick cooking spray.
Bake both sheets of meringues at the same time 45 minutes. Turn oven off. Let meringues stand in oven 1 hour or until completely cooled.