Make tomato topping: Dice tomatoes on cutting board and place in a mixing bowl. If tomatoes are very juicy, remove some seeds to prevent soggy bruschetta.

Add minced garlic, chopped basil, olive oil, balsamic vinegar, salt, and pepper to tomatoes. Stir gently with a wooden spoon to combine.

Let mixture sit at room temperature for 15-30 minutes to allow flavors to meld. This step is important for maximum flavor.

Preheat oven to 400°F or heat grill to medium-high. Line a baking sheet with parchment paper if baking.

Arrange baguette slices on baking sheet. Brush both sides lightly with olive oil using a pastry brush.

Toast bread for 3-4 minutes per side in the oven, or grill for 2-3 minutes per side using tongs, until golden and crispy with grill marks.

While bread is still warm, rub one side of each slice with the cut side of a garlic clove. This infuses the bread with garlic flavor.

Just before serving, use a slotted spoon to top each toasted bread slice with tomato mixture, letting excess liquid drain off.

Arrange bruschetta on a serving platter. Garnish with whole basil leaves, shaved parmesan, and a drizzle of balsamic glaze if desired. Serve immediately while bread is still crispy.