Combine brown sugar, butter, cinnamon and Poire William in a skillet. Cook until sugar dissolved.
Add sliced pears and cook 4-5 minutes until pears tender but still hold their shape.
Mix eggs, milk, vanilla, nutmeg, cinnamon and brown sugar.
Dip French bread in egg mixture to coat both sides.
On a griddle, melt the remaining butter and cook bread until golden brown, turning only once. ( May need more butter)
To serve, place 2 slices of French Toast on plate and top with pear mixture.
Dust with powdered sugar.