Adjust oven rack to upper middle position and preheat oven to 500°F. Heat oil and butter in a medium saucepan over medium-high heat until butter is melted. Add garlic, 1 tablespoon parsley, 1 tablespoon basil, pepper flakes, and oregano and cook, stirring frequently until aromatic, about 1 minute. Add tomatoes and sugar. Bring to a simmer and cook, stirring occasionally, until lightly thickened, about 15 minutes total. Season to taste with salt and pepper and stir in another tablespoon of parsley and a tablespoon of basil.

While sauce is cooking, heat half of pepperoni slices in a large non-stick skillet over medium-high heat until cupped and crisp around edges, about 2 minutes. Transfer to a large plate, leaving rendered fat in pan. Add four English muffin halves cut-side-down to skillet and swirl to pick up all fat. Cook until well-toasted, about 2 minutes. Transfer to a foil-lined baking sheet. Repeat with remaining pepperoni and English muffin halves.

Coat each English muffin half with sauce. Spread half an ounce of mozzarella on each English muffin, followed by 1/4 ounce of Parmesan cheese. Place 4 pepperoni slices on top of each pizza and top with a little bit more grated Parmesan.

Bake until English muffins are crisp underneath and cheese is melted and just starting to brown, about 5 minutes. Top with extra Parmesan cheese immediately after removing from oven. Drizzle with olive oil, sprinkle with remaining parsley and basil, and serve.