Using a whisk, beat together the eggs, milk, maple sugar or brown sugar, and salt in a 9-inch by 13-inch pan until the mixture is even in colour. Lay the slices of stale bread directly into the custard mixture and let them stand for 5 minutes before turning over and repeating. Most of the egg mixture should be soaked in and both sides should be quite wet.

Melt 3 tablespoons of the butter in a heavy 12-inch skillet over medium low heat. When the butter is fully melted, arrange the soaked bread in the pan. (If adding all of the bread to the pan at once would overcrowd it, fit in as much as you can without the pieces touching, and do a second batch with more butter.) Let the Simple French Toast fry slowly, lowering the heat if it begins browning too quickly, for about 5 minutes on the first side, or until the bottom appears golden brown and feels dry to the touch. Add the second installment of 3 tablespoons of butter and allow it to melt before turning the Simple French Toast pieces to fry the second side. When the second side is golden brown on the bottom, remove the pieces to a plate. Serve immediately, or hold warm for up to 30 minutes in a warm oven. Serve plain or topped with crispy bacon, maple syrup, and a freshly fried egg for a full breakfast stack.