Place whole zucchini in a medium saucepan with boiling salted water. Cook 10 minutes or until tender. Drain well.
until tender. Drain well. Cut zucchini in half lengthwise; remove and reserve pulp for other uses, leaving a firm shell. Sprinkle each shell cavity with salt and pepper; set aside.
Melt butter in a medium saucepan. Add croutons, and toss gently. Combine buttered croutons with tomatoes. Mix well. Place zucchini shells in a lightly greased shallow baking dish; spoon tomato mixture into shells. Cover and bake at 450° for 20 minutes. Sprinkle with cheese; bake, uncovered, an additional 5 minutes or until cheese melts.