Grease a 9"x13" baking dish.
Cube the bread into small 1-inch cubes, and layer with the pecans in the baking dish.
Whisk together the eggs, milk, real maple syrup, vanilla extract, salt, cinnamon, and nutmeg.
Pour the egg mixture over the bread and pecans in the baking dish.
Cover and chill for a good 4 to 6 hours or overnight.
When you're ready to bake the casserole, remove it from the fridge, and pre-heat the oven to 350° F.
Using a pastry blender, mix together the sliced butter, brown sugar, and cinnamon in a small mixing bowl.
Crumble or clump the topping over the entire casserole.
Cover the baking dish with aluminum foil, and bake at 350° F for about 25 to 30 minutes. Then uncover and bake it for an additional 15 to 20 minutes.
Once it's thoroughly cooked through, remove it from the oven and let it cool for just a few minutes.
Then slice and serve with powdered sugar and maple syrup.