Whisk together the olive oil, balsamic vinegar, basil, and garlic in a bowl. Stir in the chopped tomatoes; season to taste with salt and pepper. Cover; place in the refrigerator to marinate for 20 minutes.
Preheat oven to 350 degrees F (175 degrees C). Spread the bread slices in a single layer on a large baking pan.
Bake in the oven until golden, about 10 minutes. Remove to cool on a wire rack.
When the bread is cool, spread the semi-soft cheese evenly over each slice. Using a slotted spoon, spoon some of the tomato mixture over each slice.