Preheat the oven:
Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with cooking spray or butter.
Cook the sausage:
In a large skillet, cook the breakfast sausage over medium heat until browned and fully cooked. Drain any excess grease and set aside.
Prepare the biscuit layer:
Cut the biscuit dough into quarters and spread them evenly in the greased baking dish.
Mix the egg mixture:
In a mixing bowl, whisk together the eggs, milk, garlic powder, onion powder, salt, and pepper until well combined.
Assemble the casserole:
Sprinkle the cooked sausage evenly over the biscuit pieces. Pour the egg mixture over the sausage and biscuits. Top with shredded cheddar and mozzarella cheese.
Bake:
Place the baking dish in the preheated oven and bake for 30–35 minutes, or until the eggs are set and the biscuits are golden brown.
Garnish and serve:
Let the casserole cool for a few minutes before garnishing with chopped green onions or parsley. Serve warm and enjoy!