Remove the brie from the refrigerator before serving so it can come to room temperature.
Preheat the oven to 400 degrees.
Place the slices of bread on a baking sheet and coat with olive oil spray if desired.
Bake in the oven for 2-3 minutes, until crisp and golden brown.
Place the room-temperature Brie on a plate and serve with the crostini and grapes. Enjoy. Side Note: If you prefer melted Brie, place the Brie onto the plate, cook it in the microwave for 30-45 seconds, then add the crostini and grapes.