1. Preheat oven to 400 F.
2. Slice tomato into 6 slices (each slice should be about 1/3-inch thick). Set aside.
3. Lightly butter one side of each bread slice.
4. Place 2 bread slices, buttered side down, on work surface. Top each with 2 slices of prosciutto, then 4 basil leaves, then 4 cheese slices. Sprinkle with salt and crushed red pepper. Top each with one remaining bread slice, buttered side up.
5. Heat heavy large ovenproof skillet on medium-high heat. Add olive oil and heat for a minute or two. Place sandwiches in skillet and cook until golden on bottom, about 4 minutes.
6. Turn sandwiches over. Remove skillet from burner and place in oven. Bake about 5 minutes. Sandwich should be golden brown and cheese melted.
7. Remove skillet from oven. Carefully lift top bread slice of each sandwich and insert 3 tomato slices. Lightly press top bread slice and serve. Makes 2 sandwiches.