Mix all ingredients together in a bowl. Stir until well-combined. Pour mixture into a 9" x 12" greased pan and bake for 35-40 minutes, or until no longer soft in the center. Remove from oven and allow to cool for at least 30 minutes before slicing, otherwise it falls apart.
Once cooled, top with whipped cream, chocolate sauce and a sprinkle of cinnamon, if desired.
Store leftovers in the fridge in an air-tight container for up to 5 days.
Notes
Nutrition Facts (per slice, recipe makes 8 slices): 6 g fat, 20 g total carbs, 2 g fiber, 8 g protein