Rinse grape leaves with cold water; drain well. Pat dry with paper towels. Remove stems; discard. Set aside.
y?y?rge nonstick skillet over medium heat. Coat pan with cooking spray. Add 1 cup chopped onion; cook 7 minutes or until tender, stirring occasionally. Add rice, green onions, and nuts; cook 4 minutes, stirring frequently. Stir in water and next 7 ingredients (through cinnamon); bring to a boil. Cover, reduce heat, and simmer 15 minutes or until rice is tender. Cool slightly.
Spoon 1 rounded tablespoon rice mixture onto center of each grape leaf. Fold one side of leaf over filling. Fold opposite side of leaf over filling. Beginning at 1 short side, roll up leaf tightly, jelly-roll fashion. Steam grape leaves, covered, 10 minutes or until thoroughly heated. Cool to room temperature. Serve with yogurt and lemon wedges.