Preheat & Prep Pan: Preheat your oven to 375°F (190°C). Generously grease a 9x13-inch ceramic or glass baking dish with softened butter or nonstick cooking spray.

Brown the Sausage: In a large skillet set over medium heat, add the ground breakfast sausage. Cook for 6 to 8 minutes, breaking it into bite-sized morsels with a wooden spoon, until nicely caramelized and fully cooked through. Do not drain the rendered fat.

Make the Country Gravy: Reduce heat to medium-low. Add 2 tablespoons of butter to the skillet with the sausage fat until melted. Sprinkle the 1/3 cup of flour over the meat and stir continuously for 1 to 2 minutes to cook out the raw flour flavor and form a roux. Gradually pour in the warm whole milk in a steady stream while whisking constantly. Bring to a gentle simmer and cook for 3 to 5 minutes until thick, velvety, and bubbly. Season with garlic powder, onion powder, salt, and generous cracked black pepper. Remove from heat.

Whisk the Egg Mixture: In a medium mixing bowl, whisk together the 6 eggs, 1/3 cup heavy cream, salt, and pepper until completely smooth and lightly frothy.

Assemble the Casserole: Cut each refrigerated buttermilk biscuit into 4 quarters. Arrange half of the raw biscuit pieces in a single layer across the bottom of the prepared 9x13-inch baking dish. Sprinkle with 1 cup of shredded sharp cheddar cheese. Pour the whisked egg mixture evenly over the biscuits. Top with the remaining biscuit pieces, then ladle the warm sausage gravy generously across the entire casserole, ensuring every biscuit piece is lightly kissed with gravy. Finish with the remaining 1 cup of sharp cheddar cheese.

Bake to Golden Perfection: Bake uncovered at 375°F (190°C) for 32 to 35 minutes, until the biscuit tops are deep golden brown, the cheese is melted and bubbling at the edges, and a knife inserted into the center emerges clean without wet egg custard. (If the tops brown too quickly before 25 minutes, tent loosely with aluminum foil).

Rest, Garnish & Serve: Remove from the oven and let rest on a wire rack for 8 to 10 minutes to allow the eggs and rich gravy to set slightly. Garnish with freshly snipped chives and extra cracked black pepper. Slice into 8 generous squares and serve piping hot!