Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).

Spread the breaded cauliflower on a baking sheet and drizzle lightly with olive oil. Bake according to package directions until crispy and golden.

Meanwhile, cook the macaroni according to package directions until al dente. Drain well, but do not rinse.

Transfer the hot macaroni to a large bowl. Add the mac and cheese sauce and heavy cream, stirring until evenly combined. Pour the mixture into a 9×13-inch (23×33-centimeter) baking dish.

Gently fold the baked cauliflower into the macaroni, keeping many of the pieces near the top so they retain some of their crispiness.

Sprinkle evenly with the cornflake crumbs, mozzarella cheese, Parmesan cheese, and smoked paprika.

Bake for 20–25 minutes, or until the cheese is melted and bubbly and the topping is lightly golden and crisp. Allow to rest for a few minutes before serving.