Preheat oven to 350 degrees F. Spray a 9x13 baking dish with nonstick spray.
In a large bowl add pumpkin puree, evaporated milk, eggs, brown sugar and white sugar, stir to combine. Add cinnamon, ginger, cloves and salt into the bowl and stir again. Pour mixture evenly into the baking dish.
In the same bowl used above (no need to dirty another bowl) combine cake mix, pecans and melted butter until a crumbly mixture forms. Sprinkle this mixture evenly on top of the other ingredients in the baking dish.
Bake for 55-60 minutes or until bottom and edges are lightly browned. Remove from oven and allow to cool before serving. I recommend adding whipped cream on top for a real treat!