To make the balsamic glaze add the balsamic vinegar and brown sugar to small sauce pan and simmer until reduced by half. This should take about 10 to 15 minutes. Remove from the heat and set aside until ready to use.
Preheat your grill to high heat or preheat your oven to 450° degrees F.
Add the tomatoes to a bowl and toss with 1 teaspoon olive oil, honey, salt and pepper. If your grape tomates are small enough to fit through the gates of your grill thread them on skewers. Or you can also roast them in the oven for 10 minutes until lightly charred
Place the baguette slices on a greased baking sheet and brush each side of the bread with a little olive oil and a sprinkle of salt and pepper.
Grill the tomatoes for about 8 to 10 minutes and the baguette slices for about 3 minutes per side. Or you can toast the baguette slices in the oven on a baking sheet for about 5 minutes and the tomatoes in the oven for 10.
Preheat the broiler to high.
In personal oven safe dishes or a pan or sheet, place a few slices of toasted bread, then a few slices of fresh mozzarella and then a handful of tomatoes. Repeat so you make about three layers. Broil for 1 minute or until the cheese is melty.
Drizzle with balsamic glaze.