Take the mozzarella di bufala out of the fridge 15 minutes before serving so it comes to room temperature.
Slice the tomatoes into 1 cm rounds. Sprinkle lightly with salt and lay them on paper towel for 5 minutes to drain off excess liquid.
Drain the mozzarella from its whey and slice into 1 cm rounds, matching the thickness of the tomatoes.
Arrange the tomato and mozzarella slices on a platter, overlapping them slightly in alternating rows.
Tuck the torn basil leaves between the slices, spacing them evenly across the platter.
Drizzle the olive oil evenly over the top, making sure every slice gets some.
Season with flaky sea salt and cracked black pepper right before serving.
Finish with a thin drizzle of balsamic glaze if using, then serve immediately while the mozzarella is still cool and creamy.