For the mac and cheese: Preheat the oven to 425 degrees F.
Bring a large pot of salted water to a boil. Add the macaroni and cook according to package instructions for al dente; drain, reserving 1 3/4 cups of the pasta water.
Bring the milk, Italian seasoning and crushed red pepper flakes to a simmer in a large saucepan over medium heat. Continue cooking until the milk reduces to 1 1/2 cups, about 15 minutes. Add the cream cheese and stir until melted. Gradually whisk in both the Cheddar and Italian blend cheeses, a handful at a time, until all the cheese is melted and the sauce is smooth.
Add the cooked macaroni and reserved pasta water to the cheese sauce and stir to combine. Stir in the marinara sauce, sun-dried tomatoes and pepperoni and adjust the seasoning with salt. Pour into a 9-by-13-inch baking dish. Toss the bread crumbs, Parmesan and sun-dried tomato oil together in a small bowl until the crumbs are moistened and sprinkle evenly over the macaroni and cheese. Bake until bubbly and lightly browned, about 10 minutes.
Copyright 2018 Television Food Network, G.P. All rights reserved.