Combine egg whites (at room temperature), cornstarch, and flavorings; beat until frothy. Gradually add sugar, 1 tablespoon at a time, beating until stiff peaks form. Fold in pecans.
Line baking sheets with waxed paper. Drop mixture by heaping tablespoonfuls onto waxed paper. Bake at 250° for 35 minutes. Cool away from drafts. To serve, gently remove from waxed paper.