Preheat oven to 350 degrees F. Spray a 9 by 13-inch baking pan with cooking spray; set aside.
Beat cake mix, butter, and egg in a large bowl with an electric mixer on low speed. Beat into well combined crumbs. Press cake mixture evenly into prepared pan, set aside.
Blend all potato filling ingredients in food processor until smooth. Spread evenly over crust layer.
Combine all topping ingredients in small bowl. Sprinkle over and press into sweet potato filling. Bake in preheated oven for 30 to 35 minutes, until just set and tester inserted comes out clean.
Recipe courtesy of Sandra Lee, 2008