Spray two 9x13-inch baking pans with cooking spray. Place French toast pieces evenly in the bottoms of prepared pans; set aside.
In a medium bowl, whisk together eggs, milk, 1 cup of the maple syrup, and the pumpkin pie spice until well combined. Pour evenly over French toast slices in each pan. Cover with plastic wrap; let sit for 1 hour, occasionally pushing French toast down into mixture.
Preheat oven to 350 degrees F. Remove plastic wrap and place pans in oven. Bake about 1 hour or until golden brown.
In a small saucepan, heat the remaining 1 cup maple syrup, the marmalade, and sliced banana over medium-low heat until heated through. Serve warm over French toast.