Slice angel food cake into 1" thick slices. Whisk together 4 eggs, 2/3 c milk, 1 tsp vanilla, 1/2 tsp cinnamon, and 1/4 tsp salt until combined. Place slices of cake into egg mixture, let sit 2 min per side. Heat skillet over med heat. Spray w/non-stick cooking spray. Cook cake slices until the bottom is brown. Flip to the other side. Repeat with the remaining slices. Heat 1 c maple syrup, 3 oz cream cheese, and 1/2 tsp cinnamon in a small saucepan, whisk vigorously. Pour over french toast.