Preheat oven to 400°F and grease a 9×13-inch baking dish.
In a skillet over medium-high heat, cook onion, bell pepper, and beef sausage until fully cooked.
Season with garlic powder, Italian seasoning, ½ teaspoon salt, and ¼ teaspoon black pepper.
Stir in 4 slices of chopped turkey bacon, then transfer mixture to baking dish.
Add 1 cup cheese and frozen tater tots; mix and spread evenly.
In a bowl, whisk eggs and milk until smooth. Season with remaining salt and pepper.
Pour egg mixture evenly over casserole.
Top with remaining cheese and turkey bacon.
Bake for 25–35 minutes until set and golden.
Optional: Broil 1–2 minutes for a crispy top.
This Tater Tot Breakfast Casserole is ready when the center is firm and the top is golden brown.