Pre- heat oven to 350*. Remove 1 cup of the cake mix and set aside. Combine the remaining cake mix with the 1/2 c of melted butter. Add one egg and mix until smooth. Spread the mixture on the bottom of a greased 13×9 pan and set aside.
Mix the pumpkin pie mix with 2/3 c. milk and two eggs. Pour this over the crust mixture in 13×9 pan.
Combine the 1 cup cake mix you set aside with the 1/4 c. softened butter, the cinnamon, and the sugar. Mix until crumbly and sprinkle over the top of the pumpkin in 13×9 pan.
Bake at 350* for 50-55 minutes or until slightly golden. After it has cooled, refrigerate for about 2 hours. Cut into squares and top with some Cool Whip. Enjoy!