Grease a 9x13 inch pan and preheat the oven to 350 degrees F.
Measure out 1 cup of the yellow cake mix into a small mixing bowl. Set aside (it's for the top).
In a large bowl or stand mixer, beat together the remaining cake mix, melted butter, and egg (if your butter is very hot, wait until it cools before adding the egg. Or be impatient like me and add it while the mixer is on.)
Spread the mixture into the bottom of the prepared pan.
In the same bowl, add pumpkin, sugar, eggs, cinnamon, ginger, cloves, and nutmeg. Beat until combined, then add the evaporated milk. Beat well (careful not to splash).
Pour the mixture on top of the first layer.
Add the cut butter to the cake mix and use a pastry knife of fork to cut until it looks crumbly. (There should be pea-size pieces of butter).
Sprinkle this mixture over the cake.
In another small bowl, combine the cinnamon and 1/2 cup sugar. Sprinkle over the cake.
Bake at 350 for about 60-65 minutes, or until a toothpick comes out clean and the center is set.
Serve warm with ice cream or cold with whipped cream!