Preheat oven to 350 degrees and cook the pasta accordingly to package directions for al dente. Drain and set aside.
Chop about ½ cup of the pepperoni, leaving 10-12 slices whole.
Melt the butter, adding the flour, garlic and onion powder and Italian seasoning in large saucepan set over medium heat. Whisk together until it forms a paste.
Slowly whisk in the milk. Continue to whisk and bring to a boil. Reduce heat to medium-low and simmer for 2-3 minutes, until it thickens slightly and flavors marry.
Remove sauce from heat and whisk in the white cheddar cheese.
Toss in the pasta and chopped pepperoni.
Transfer to greased 9 x 13-inch baking dish (or any 3-quart casserole, baking dish or cast iron skillet).
Top with sliced pepperoni. Spoon Prego® Traditional Italian sauce on top. Sprinkle with the mozzarella and Parmesan cheese.
Bake uncovered for 15 to 20 minutes or until golden and bubbling.
Remove and allow to sit for 5 minutes before serving. Serve with additional pasta sauce, cheese and chopped parsley, if desired.
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