In a small bowl, stir together oil, basil and salt.
Cut cheese in half horizontally. Place bottom half cut side up on a serving plate. Spoon half of the oil mixture over cheese. Place half of pear slices on top in a flat layer. Place remaining piece of cheese on top, cut side down. Spoon remaining oil over and layer with remaining pears. Cover with plastic wrap. Let stand at room temperature for 2 to 4 hours or until cheese is soft.
Meanwhile, cut the half-baguette into thin slices. Toast and serve with the brie.