Preheat oven to 350 degrees F (190 degrees C). Grease the bottom of a 9x13 inch pan.
Pour one cup of yellow cake mix into a medium size mixing bowl; set aside.
Combine remaining cake mix, 1/2 cup melted butter and 1 egg; mix well. Press into the baking pan.
Combine pumpkin pie filling, 2 eggs and milk in a medium size mixing bowl; mix until smooth. Pour evenly over the crust in the 9x13 inch pan.
Pour the sugar and cinnamon into the mixing bowl containing the 1 cup of yellow cake mix. Cut in the butter until the mixture looks crumbly. Sprinkle this mixture over the pumpkin filling.
Bake for 45 to 50 minutes or until a knife inserted into the bars come out clean. Let cool before cutting.
