Preheat the oven to 350°F. Spray a 9x13-inch baking dish with non-stick cooking spray.

Over medium-high heat, crumble the sausage in a large skillet and cook for 5 minutes, or until browned. Reduce heat to low and add butter. When the butter is melted, add flour, 1 teaspoon ground black pepper, and 1/2 teaspoon seasoned salt, then whisk to combine. Bring just to a simmer, add 1/2 cup milk, and whisk until fully incorporated.

Increase the heat to medium. Stir constantly until the mixture begins to thicken. Gradually add the remaining milk, 1/4 cup at a time, whisking thoroughly until the gravy is smooth and thickened slightly. Set aside.

Cut biscuit dough portions into quarters then arrange them in the baking dish in a single layer.

In a medium bowl, whisk the liquid egg replacer with the remaining 1/2 teaspoon seasoned salt and 1/4 teaspoon ground black pepper. Pour the egg mixture over the biscuit dough.

Sprinkle the cheese over the biscuits.

Pour gravy over the cheese layer; use a spatula to spread the gravy to cover the entire casserole.

Bake for 45 minutes, or until golden and bubbly. Let the casserole rest for 10-15 minutes then serve warm.

For an Overnight Casserole: This casserole can be assembled the night before and baked in the morning. Remove the foil-covered casserole from the refrigerator and preheat the oven to 350°F. Bake, covered, for 30 minutes then remove the foil cover and continue baking for an additional 20-30 minutes, until golden and bubbly. (Depending on your oven, the casserole will need a good 45-60 minutes to fully heat and cook throughout.)