In a large bowl whisk together the flour, baking powder, salt, and cinnamon. Set aside. In a smaller bowl stir together the ricotta cheese, egg yolks, brown sugar, and bourbon (or vanilla extract) until just combined. Now combine the ricotta mixture with the dry ingredients and milk. Stir until just combined. With an electric mixer beat the eggs whites until very frothy and peaks just begin to form. Gently fold the egg whites in with the rest of the mixture.