Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
Arrange the baguette slices in a single layer on the prepared baking sheet. Brush the tops lightly with olive oil.
Place the baking sheet in the oven and toast the bread for 7 to 9 minutes, or until the edges are golden and crisp but the center is still slightly tender.
While the bread toasts, add the diced tomatoes, garlic, salt, pepper, basil, and olive oil to a medium bowl. Stir gently to combine.
Spoon the tomato mixture evenly onto each piece of toast. If desired, drizzle a little more olive oil and some balsamic vinegar over the top.
Serve immediately.