Spread butter on both sides of each bread slice, and toast lightly under a broiler for 1-2 minutes each side (you can also use a toaster).
When bread is golden, lay the pieces on a baking sheet and layer with a slice of pear and Brie. Finally, wrap with prosciutto and bake at 350 degrees for 10-13 minutes.
When the cheese has melted, remove from oven and allow to cool slightly before topping with fresh basil and serving.