Preheat oven to 350°F. Coat a 13x9-inch baking dish with cooking spray.
Cook ground sausage and hot ground sausage onion, green bell pepper and red bell pepper in a large skillet over medium-high heat, stirring often, until they are crumbled and browned, about 10 minutes. Remove from heat; drain excess fat from the pan.
Wipe pan clean with a paper towel. Add butter to skillet and melt. Add hash browns to the skillet. Sauté in melted butter over medium heat just until excess moisture is removed and the potatoes begin to brown, around 5 minutes. Remove from the heat.
In a large bowl mix together sausage mixture, hash browns, 1 tsp seasoned salt, 1 tsp black pepper and 2 cups shredded cheese. Pour into baking dish.
In the same bowl use a whisk to combine eggs, half and half, 1 teaspoon seasoned salt and 1⁄2 teaspoon pepper, granulated garlic, onion powder, dry mustard and hot sauce (if using) in a medium bowl.
Pour egg mixture over hash brown mixture. Use a fork to gently move the hash browns just enough to let the egg fully saturate the potatoes. Sprinkle with remaining 1 cup cheese.
Bake in preheated oven until the center is set when gently shaken, about 40-50 minutes. Sprinkle with parsley and chives, then slice and serve.