Layer the slices of bread in a greased 9-inch (23 cm) square baking pan.
Whisk together the eggs, milk, cream, vanilla, cinnamon, and nutmeg and pour over the bread.
Cover and refrigerate overnight. In the morning, mix together the brown sugar and chopped nuts and sprinkle over the bread.
Bake in a preheated 350F (180C) oven for 50 to 60 minutes, until puffed and golden. Serves 6 to 8.