Preheat oven to 400ºF. Place the butter on the stove to soften while you prepare other ingredients.Slice your loaf of bread in half horizontally and place on a baking sheet. Peel and mince the garlic (I like to use a mini cheese grater) and place in a small bowl. Slice the tomatoes, mozzarella, and basil while you wait for the butter to soften.Once soft, mash the butter with the garlic (and salt if necessary) and spread evenly on the bread. Top with mozzarella slices and bake in oven for about 12 minutes.Remove from oven and add tomatoes, then return to oven for about 5-6 minutes. The cheese should get a little bubbly and the tomatoes will soften just slightly.Remove from oven and top with basil and drizzled balsamic. Serve!