Preheat your oven to 350 degrees. Spray a 9 by 13 inch casserole dish with cooking spray.
Spray a large skillet with cooking spray and heat over medium high heat. Break up the sausage and cook until no longer pink
Add the onion, green bell pepper, garlic, and red bell pepper and cook, stirring occasionally, until the onions are translucent, about five minutes.
While the veggies are cooking, whisk the eggs. Add to the eggs, the milk, salt, salsa, 1 1/2 cup cheese, and bread. Mix to combine.
Add the veggie and meat mixture, and stir together.
Pour the whole mixture into the prepared pan and top with 1 cup cheese.
Bake for 55 minutes or until the eggs are set.
Let the casserole sit for 10 minutes before cutting into it.