Preheat your oven to 350°F. While it heats, grease a 9x13 inch baking dish with butter or cooking spray. Unroll the thawed crescent roll dough and press it evenly across the bottom of the prepared dish, sealing any perforations together to create a continuous base layer. This foundation will provide a wonderful texture and help hold the fillings in place during baking.

In a skillet over medium-high heat, brown the hot sausage, breaking it into small crumbles as it cooks, about 5-7 minutes. Drain off any excess fat and set the cooked sausage aside. While the sausage cooks, if using fresh diced potatoes instead of frozen, you can prep them now—frozen potatoes are ready to use as-is. Have your shredded cheddar cheese measured and ready.

Spread the cooked sausage from Step 2 evenly over the crescent roll base. Next, distribute the potatoes in an even layer, then top with the shredded cheddar cheese. I like to layer the cheese last so it gets nice and melty on top during baking. Keep the oven preheating while you prepare the egg mixture.

In a mixing bowl, whisk together the 6 eggs and 2 cups whole milk until well combined and smooth. Pour this mixture evenly over the layered casserole, making sure the liquid distributes throughout so every bite will have egg and milk. Let the assembled casserole sit at room temperature for a few minutes while you do a final oven check—this helps ensure even cooking throughout.

Place the casserole into your preheated 350°F oven and bake for approximately 45 minutes, or until the eggs are completely set but the top is still slightly golden. The center should jiggle only slightly when gently shaken—it will continue cooking slightly as it rests. I find that setting a timer for 40 minutes and then checking every few minutes helps prevent overbaking.

Remove the casserole from the oven and let it stand at room temperature for 10 minutes before cutting and serving. This resting period allows the egg to fully set throughout and makes portioning much cleaner. This casserole is perfect served warm and can be made the night before and refrigerated unbaked—just add 10-15 minutes to your baking time if baking from cold.