Slice French bread into one-inch slices. Arrange slices overlapping in a greased 9x13 baking dish.
In a large mixing bowl whisk, half-and-half, eggs, milk, sugar, vanilla, cinnamon, nutmeg, and allspice until well combined but not too bubbly.
Pour milk and egg mixture evenly over the bread slices, spoon mixture in between the slices.
Cover tightly with aluminum foil and refrigerate overnight.
The next day, preheat oven to 350 F.
Combine butter, brown sugar, pecans, cinnamon, and nutmeg in a small mixing bowl until combined. Spread topping evenly over the bread and bake for 40 minutes, or until lightly golden on top. Enjoy!
