Butter a 9 in. by 13 in. casserole pan.
Place sliced bread in the bottom of the pan. Make sure to leave at least 1 - 1/2 inch of room at the top of pan.
In a blender, add eggs, milk, half and half, vanilla, cinnamon, and nutmeg. Blend.
Pour milk and cream mixture over the sliced bread in the casserole.
Cover and place casserole pan in the fridge overnight.
Mix topping. Put butter, corn syrup, brown sugar, and chopped nuts in a bowl or large measuring cup and mix together. Save for later.
In the morning, preheat oven to 350.
Pull out casserole dish. Spoon topping over the French bread. Spread topping lightly.
Place French toast in the oven and cook for 45 minutes.
Check oven French toast. French toast should be puffed and lightly browned on top. Place foil over top loosely, if needed, and bake for another 5 minutes.
Baked French toast will be golden brown on top, while the casserole will be moist but custard liquid gone. Wait 5 minutes before portioning out. Enjoy!