Preheat oven to 350 degrees. Coat a 9×9 inch casserole dish with cooking spray. Set aside.
Place bacon on a microwave-safe plate lined with paper towels. Cover bacon with more paper towels. Cook in microwave for about 4 minutes until crisp. Blot, cool slightly and crumble bacon.
Add frozen tater tots into the casserole dish and arrange them into a single layer. Sprinkle sausage pieces evenly across the top of tater tots. Sprinkle crumbled bacon over top of the sausages. Sprinkle shredded cheddar cheese over top of the bacon.
In a large mixing bowl, combine eggs, milk, scallions (if using), a little salt black pepper and red pepper flakes, if desired. Beat eggs and seasonings with a whisk. When beaten, pour eggs over top of cheese layer in the casserole dish.
Bake for 50-60 minutes or until eggs are cooked through and a toothpick inserted into the center of the casserole comes out clean. Cool slightly and cut into 6 slices.