Toss the fresh berries with the balsamic vinegar to coat, and spread evenly on a rimmed baking sheet. Roast the berries at 400F in the oven for about 8 minutes (optional). Otherwise, skip to next step.
Brush the baguette slices with the olive oil and then toast or grill the bread slice, flipping after about 4 minutes so that both sides are slightly crispy.
Top the toasted bread slices with a dollop of the ricotta and then add a few balsamic berries.