Preheat oven to 350 degrees F. Spray a 13x9x2 inch baking dish with cooking spray. Set dish aside. In a large skillet, melt butter over medium heat. Add sliced green onions. Cook for 5 minutes or until onions soften. Stir in garlic and cook for 2 minutes more, stirring often. Sprinkle with salt and pepper. Remove from heat.
In a large bowl, stir hash brown potatoes, sour cream, heavy cream, soup, bell pepper, smoked cheddar cheese and half of bacon. Add green onion mixture to bowl. Pour into prepared dish and spread evenly. Cover with foil and bake for 35 minutes. Remove from oven, stir contents, and sprinkle sharp cheddar cheese evenly over top. Bake for 10 minutes. Sprinkle with French fried onions and remaining half of bacon. Bake for 5 minutes more.