Place rice in a large colander, and rinse until water runs clear. Combine rice, 8 cups water, and salt, and soak 2 hours. Drain, pouring salted water into a large nonstick Dutch oven. Bring to a boil, and add rice. Return to a boil, and cook 12 minutes, gently stirring twice to keep rice from sticking to bottom of Dutch oven. Drain rice; rinse with warm water.
Dissolve saffron in 2 tablespoons hot water. Set aside.
Combine green onions and next 3 ingredients in a bowl.
Add half of melted butter to nonstick Dutch oven. Drizzle with 1 tablespoon saffron mixture. Spoon about 1 cup rice over butter; top with about 1/2 cup green onion mixture, and top with garlic cloves. Repeat layers with remaining rice and green onion mixture, forming a cone shape. Sprinkle with cinnamon, and drizzle with remaining half of butter, remaining 1 tablespoon saffron mixture, and remaining 2 tablespoons hot water.
Place a clean cotton dish towel over Dutch oven (make sure it doesn't touch the burner), and cover firmly with lid to prevent steam from escaping. Cook over high heat 2 minutes; reduce heat to low, and cook 12 minutes. Remove from heat, and cool 5 minutes.
Scoop rice, using a spatula, onto the center of an oval serving platter, leaving the crisp bottom intact. Gently lift crisp bottom layer with spatula, and serve on a separate plate, or crumble over rice on serving platter.