Preheat oven to 350 degrees. Measure out 1 cup of the cake mix and set aside. Mix remaining cake mix with ½ cup melted butter and 1 egg. Press mixture lightly into the bottom of a 9×13 pan lined with parchment.
Mix pumpkin butter with 2 eggs lightly beaten and milk. Pour over cake mixture in pan.
Mix reserved cake batter with flour, sugar, ¼ softened butter and cinnamon. Crumble on top of pumpkin layer. You may have some holes.
Bake for 35-40 minutes or until golden. Cool in pan and then lift parchment to remove. Dust with a mixture of powdered sugar and cinnamon.