Preheat your oven to 375°. Butter a 12" x 8"baking dish.
Over medium heat, melt the butter. Add the green pepper and onion. Cook for about five minutes, until soft. Season with salt and pepper. Take off the heat and stir in the bread.
Place half of the bell pepper mixture evenly across the bottom of the baking dish.
Sprinkle with half the mozzarella cheese.
Layer the tomatoes in the pan. Season with salt and pepper.
Top tomatoes with the remaining half of the bell pepper mixture.
Top that with the remaining 1½ cups mozzarella cheese, and sprinkle as desired with shredded Parmesan. Season with salt and pepper.
Bake for 30 minutes or until the top is golden. When hot out of the oven, sprinkle with basil. Cool at least 10 minutes, then slice or scoop, and serve.