Preheat the oven and prep the dish. Heat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish with olive oil spray or a thin film of oil.

Cook the base. Boil the high-protein pasta in salted water until just shy of al dente (1–2 minutes less than package directions). Drain well. If using roasted cauliflower, roast at 425°F (220°C) with a little oil, salt, and pepper for 20–25 minutes until tender and golden.

Brown the meat. Warm a large skillet over medium-high heat. Add olive oil if needed, then the ground turkey. Season with salt, pepper, and Italian seasoning. Cook, breaking it up, until browned and cooked through, about 6–8 minutes. Stir in the garlic for the final minute.

Add sauce and veggies. Reduce heat to medium. Stir in marinara, bell peppers, mushrooms, red onion, and red pepper flakes if using. Simmer 3–5 minutes to soften the veggies slightly and thicken the sauce.

Make the creamy protein layer. In a bowl, mix cottage cheese with half the Parmesan and a pinch of black pepper. For a smoother texture, blend the cottage cheese first.

Assemble the casserole. Spread the pasta (or roasted cauliflower) evenly in the baking dish. Spoon the meat-and-sauce mixture over the top and gently toss to coat. Dollop and spread the cottage cheese mixture evenly over everything.

Add the “pizza” finish. Sprinkle mozzarella and remaining Parmesan over the top. Arrange turkey pepperoni across the surface. Add extra peppers or mushrooms if you like a loaded look.

Bake until bubbly. Cover loosely with foil and bake for 15 minutes. Remove foil and bake another 10–12 minutes, until the cheese is melted and golden around the edges.

Rest and serve. Let it rest for 5–10 minutes so it sets. Slice and serve hot. Garnish with chopped fresh basil or parsley if you have it.