Cook the sausage. Put the onion powder and the ground sausage into a skillet and fry them. Make sure to break up any chunks and add salt and pepper as it's cooking. Cook until the sausage is browned all the way.
Spray your baking dish with a nonstick spray and preheat the oven to 350 degrees.
Add the biscuits. Put the quartered biscuits on the very bottom of the baking dish.
Layer the sausage. Once the sausage is done cooking, use a spoon, scoop it out of the skillet, and put it on the biscuits. Be sure to leave the grease and also a tiny amount of the sausage in the skillet, as you'll be using this to make the homemade gravy in a bit!
Add the shredded cheese on top of the sausage that is in the baking dish.
Whisk ingredients. Break the eggs and whisk them with the brown sugar and milk using a clean bowl. Once this mixture is whisked well, pour it over the top of the cheese in the baking pan.
Put the butter in a greased skillet on medium heat and melt it. Add the flour and stir it. Cook this mixture for 3 minutes.
Add in the salt, pepper, thyme, and slowly add the milk. Whisk this on medium heat until it's thick.
Take the thickened gravy mixture and pour it over the top of the casserole.
Add the baking pan to the oven and bake for 35-40 minutes. Make sure that the eggs and biscuits are fully cooked. If they are not, cook in 5-minute increments until cooked all the way.