Mix first 7 ingredients in a bowl. Let sit for an hour so the juice of the tomatoes can blend with the other flavors. This can be done hours ahead of time. Go light on the salt at first as the capers may provide enough salt depending on the type being used.
Slice the baguette in 3/4" thick rounds and grill or broil to toast on both sides. You want the bread slightly browned, but not burnt.
As soon as the baguettes come off the heat, peel the garlic and slice in half. Rub the fresh cut garlic side on one side of each slice of bread. Place garlic side up on a serving platter.
Just before you are ready to serve, spoon the tomato mixture on top. Serve immediately.
Notes
The picture shows bruschetta without capers, with capers, and with shaved parmesan.Options:
You can add chopped fresh mozzarella. The pieces should be about the same size as the tomatoes. This will turn the dish vegetarian instead of vegan, but depending on your guests, it may work.
You could also sprinkle fresh shaved parmesan on the top (shown in the picture). Again, this will make the dish vegetarian but not vegan.