Brown the meat. Cook the sausage or ground beef in a skillet over medium heat, breaking it up as it cooks, until fully browned with no pink remaining, about 7–8 minutes. Drain excess fat.
Balance the sauce before it goes in. In a bowl, stir the sugar, oregano, and garlic powder directly into the pizza sauce. Mix this in now, before baking, rather than trying to fix the flavor with a drizzle of something on top afterward. Jarred sauce tends to taste more acidic once it’s baked down and concentrated, and stirring the sugar in at this stage lets it distribute evenly through the whole sauce instead of sitting as a surface-level patch the difference is subtle but noticeable, especially with a more acidic sauce brand.
Toss the biscuit pieces. Preheat the oven to 375°F. Cut each biscuit into quarters and toss the pieces with about two-thirds of the seasoned sauce in a large bowl, making sure each piece gets coated.
Layer the casserole. Spread the sauced biscuit pieces evenly in a greased 9×13-inch baking dish. Scatter the browned meat and pepperoni over the top, then pour the remaining sauce over everything. Pro tip: don’t press the biscuit pieces down flat — leaving them a little loose and uneven helps the whole dish bake up with craggy, golden edges instead of a flat, uniform surface.
Add the cheese. Sprinkle 2 cups of the mozzarella evenly over the top, followed by the parmesan and a few extra pepperoni slices for good measure.
Bake. Bake, uncovered, for 20–22 minutes, until the biscuits are cooked through and golden and the cheese is fully melted and bubbling at the edges. If the top is browning faster than the biscuits are cooking through, loosely tent it with foil for the last 5 minutes.
Finish and rest. Sprinkle the remaining 1 cup of mozzarella over the top and return to the oven for 2–3 minutes, just until melted. Let the casserole rest for 5 minutes before serving it firms up slightly and is much easier to portion.
Serve. Top with fresh basil or parsley and serve warm.
