Pour apple sauce into greased 13 x 9 x 2 inch baking pan; set aside. Combine gelatin and cinnamon; sprinkle over apple sauce. Prepare cake mix according to package directions substituting yogurt for eggs and oil. Pour batter over apple sauce mixture. Bake at 350°F for 45 minutes or until wooden pick inserted near center comes out clean. Cool 5 minutes; invert onto serving platter and cool.