Slice the bread in half lengthwise and place cut side up on a baking sheet. Broil on low for about 3 to 4 minutes until lightly toasted.
Spread 1 tablespoon basil pesto onto each half of the toasted sandwich bread.
Layer 3 slices of fresh mozzarella onto the bottom half of the sandwich bread, then top with tomato slices, basil leaves, and the remaining 3 slices of mozzarella.
Close the sandwich and serve, or wrap in parchment paper and refrigerate for up to 4 hours.
Notes
Italian filone bread: This traditional Italian bread is similar to a French baguette, which makes it perfect for a caprese sandwich! If you can't find it at the store, substitute with a soft French baguette or ciabatta bread.Serving suggestions: This caprese sandwich is a great packable lunch for picnics, hikes, or beach days! If you want to prepare it ahead of time, wrap it up tightly in parchment paper and refrigerate until ready to eat. It will stay fresh for a few hours this way.