In a 1-quart casserole stir together orange juice, cornstarch and 1/4 t ground cinnamon. Micro-cook, uncovered, on 100% power for 1 1/2 to 2 minutes or till thickened and bubbly, stirring every 30 seconds. Stir in drained mandarin orange sections and finely shredded orange peel. Micro-cook, uncovered, on 100% power for 1 to 1 1/2 minutes or till mixture is heated through. Meanwhile for dumplings, stir together Bisquick and 2 T sugar. Add milk, stirring just till moistened. Drop mixture into four mound atop the hot orange mixture. Micro-cook, uncovered, at 50% power for 6 to 7 minutes or till dumplings are just set. Stir together the 1 t sugar and dash of ground cinnamon. Sprinkle sugar mixture atop dumplings.