Pour balsamic vinegar into a small saucepan, and add the crushed garlic; bring to a boil over medium-high heat. Reduce heat to medium-low, and simmer until the vinegar has reduced to 1/4 cup. Set aside, and cool to room temperature.
Divide the lettuce leaves among 4 salad plates. Arrange the tomato slices on top of the lettuce, then place the mozzarella on top of the tomatoes. Sprinkle the salads with the red onion, raspberries, and sliced black olives. Season with dried basil, salt, and pepper; drizzle with the olive oil and balsamic vinegar.