Rinse the tomatoes and basil leaves in cold water, then pat dry the basil leaves with paper towels.
Slice the mozzarella and tomatoes into ½ slices.
Sprinkle the salt and black pepper over the top of the tomato and mozzarella slices.
Place a frying pan (or griddle) on the stovetop over medium heat.
Coat the bottom of the pan with olive oil and place the ciabatta bread face down in the pan. Heat until lightly toasted (2-3 minutes).
Remove the bread from the pan and place on a plate.
Add a layer of baby spinach on the bottom part of the roll.
Drizzle the balsamic vinegar and olive oil over the top of the spinach leaves.
Add a layer of seasoned mozzarella cheese over the spinach.
Add a layer of tomatoes on top of the mozzarella, and sprinkle the chopped parsley over the tomato slices.*You can drizzle more olive oil and balsamic vinegar over the tomatoes if desired.
Place the basil leaves on top of the tomatoes, then add the top of the bun.