1. Bring 3/4 cup water to a boil in a saucepan; stir in couscous. Remove from heat; cover and let stand 5 minutes. Fluff couscous with a fork. Transfer to a bowl.
2. Cook edamame according to package directions; drain. Rinse with cold water; drain.
3. While edamame cooks, combine orange juice and next 5 ingredients (through pepper), stirring well with a whisk. Add edamame, spinach, and next 3 ingredients (through cranberries) to couscous. Pour orange juice mixture over salad; toss to coat. Sprinkle with chopped peanuts.