• Preheat the oven to 375°F and spray a 9x13-inch baking dish with cooking spray.

Biscuit Dough

• To a medium bowl, add flour, baking powder, sugar, and salt. Use a whisk to sift the ingredients.
• Pour in the buttermilk and stir until mostly combined, being careful not to overwork the batter.
• Pour the melted butter into the baking dish. Place the dough on top of the butter and use a spatula (or your hands) to evenly spread the dough out to the edges of the pan.

Casserole

• To a large skillet over medium heat, add pork sausage and onion. Cook until the pork sausage is browned with no pink remaining (about 8 minutes). Drain excess grease and add the pork in an even layer over the dough.
• In a large bowl combine eggs, milk, salt, and pepper. Whisk until combined.
• Fold in both cheeses. Pour the egg and cheese mixture over the sausage.
• Bake 40 minutes, or until a knife inserted in the center comes out clean.
• Let the breakfast bake rest for about 10 minutes before cutting and serving. This allows the butter to be absorbed into the biscuits. Top with parsley for garnish (optional).