Boil the spaghetti noodles until just al dente. Reserve ½ cup of pasta water before draining. Set the pasta aside.

Heat olive oil in a skillet over medium heat. Add diced onions and bell peppers, cooking for 2-3 minutes until soft. Stir in pizza sauce, garlic powder, and Italian seasoning. Add a splash of pasta water to thin it out slightly. Sprinkle in sugar, then taste test. Adjust seasoning if needed. Stir in cubed pepperoni and let it simmer for 5 minutes.

Add the cooked pasta to the sauce, mixing well. Use tongs to coat every single noodle-no naked pasta here! If you’re feeling extra cheesy, mix in some shredded mozzarella at this step.

Preheat oven to 375°F (190°C). Grease a cast iron skillet or baking dish with butter. Pour the spaghetti mixture into the pan and spread it evenly. Sprinkle a generous amount of mozzarella cheese on top. Arrange sliced pepperoni on top like a pizza. Bake for 10-15 minutes, or until the cheese is melted and bubbly. If you want it extra golden, broil for 1-2 minutes at the end.

Mix semi-melted butter, garlic paste, Italian seasoning, Parmesan cheese, and parsley in a bowl. Slice the French bread in half lengthwise. Spread the garlic butter mixture evenly over the bread. Bake in the oven at 375°F (190°C) for 10 minutes, until crispy and golden.

Remove the baked spaghetti from the oven and let it rest for 5 minutes. Slice into portions and serve with garlic bread on the side. Optional: Add a little Parmesan or red pepper flakes for extra flavor.