Preheat oven to 350 degrees. In a 13x9 inch glass pan, lay 6 slices of bread on each half of the pan (they will overlap).
In a large bowl, whisk together eggs, milk, coconut sugar, vanilla, cinnamon, and nutmeg. Pour mixture over the bread, making sure to get between each slice so that everything is fully saturated. Cover with aluminum foil and bake. (At this point you can cover, and let it sit in the fridge overnight, then pull it out when ready to bake)
Meanwhile, mix together all ingredients from the Pecan topping. Once the casserole has been baking for 30 minutes, uncover it, and spread the pecan topping evenly over the top (cut around the perimeter of the bread to loosen the edges so the pecan mixture can drip into the bottom of the pan). Bake uncovered for another 10 minutes.
Once it is finished, let the casserole rest for 5-10 minutes to set the topping. Serve with maple syrup and enjoy!