Preheat oven to 350℉ and grease a 9×13 inch baking dish. Spread the frozen hash browns into the casserole dish and place in the oven to thaw while the oven preheats, about 10-15 minutes.
Heat a large skillet over medium heat. Crumble or chop the sausage and add to the pan. Cook until browned, then remove from heat and set aside.
In the prepared dish with the thawed hash browns, add the sausage, onion, red pepper, green pepper and cheese. Gently mix the ingredients together in the dish and spread them evenly.
In a large bowl, whisk together the JUST Egg, flour, baking powder and salt. Pour the egg mixture over the hash brown mixture in the baking dish.
At this point, you can cover and refrigerate overnight, or bake immediately. Bake uncovered for 55-60 minutes, until the "egg" mixture is firm and cooked. If refrigerated overnight, it will need to bake longer, around 65-75 minutes.
Serve immediately with hot sauce, if desired.