Add the tomatoes, garlic, 3 tablespoons extra-virgin olive oil, red pepper flakes, basil and balsamic vinegar to a bowl. Season with salt and pepper. Let sit at room temperature while you toast the bread.
Slice bread and add to a baking sheet in a single layer. Toast in the oven until golden brown about 5 minutes. Top the bread with tomatoes and drizzle with remaining olive oil right before serving.