Heat the oven to 375°F and grease a 9-by-13-inch dish. Cook shells 2 minutes short of done and drain.
Simmer tomatoes, garlic, basil, 1/2 teaspoon salt and pepper for 8 minutes. Mix ricotta with remaining salt.
Toss shells with tomato sauce, mozzarella and fontina. Spread half in the dish, dot with ricotta, then add remaining pasta.
Mix panko, 1/2 cup Parmesan and olive oil and sprinkle over the pasta; add remaining Parmesan.
Bake for 30 to 35 minutes until bubbling and crisp on top. Rest 10 minutes.