Spray a 13x9 inch-baking dish with cooking spray. Preheat oven to 350 degrees.
Wash and slice EIGHT of the pears (no need to peel). Place on a cookie sheet lined with aluminum foil and sprayed with cooking spray. Drizzle the pears with agave nectar and sprinkle with kosher salt. Roast about 45 minutes or until soft and slightly caramelized. Set aside.
In a medium sized bowl, combine the milk, eggs and vanilla. Whisk together until combined. Set aside.
Slice bread into about ½ inch slices, and lay enough down to cover the bottom of the baking dish.
Arrange the roasted pears over the top of the bread. In a small bowl, combine the brown sugar and cinnamon. Sprinkle over the pears.
Add another layer of sliced bread.
Pour milk/egg mixture over the top. Press down firmly to make sure all bread has been soaked in the mixture.
Thinly slice the remaining 2 pears lengthwise (no need to remove core). Lay on top of the casserole. Cover firmly with plastic wrap. Refrigerate overnight.
When ready to bake: Preheat oven to 350 degrees. Bake French toast for approximately 30 minutes or until custard is set.
Remove from heat and drizzle with Salted Caramel Sauce.
CARAMEL SAUCEIn large saucepan, melt butter. Whisk in flour and brown sugar. Slowly stir in heavy cream, and cook until thickened over medium heat – let mixture come to a boil to cook off any raw flour taste.
Remove from heat and stir in vanilla.
Serve warm, or sauce can be chilled and reheated in the microwave.
Caramel Sauce Adapted from The New Ark Cookbook