Grease a 9x13-inch baking dish, and preheat the oven to 350 F.
Make the base layer: in a medium-sized bowl, combine the yellow cake mix (reserve one cup for later), one egg, and one stick of melted butter until well combined. Press this mixture into the bottom of the prepared baking dish.
Into the same mixing bowl, place the pumpkin puree, three eggs, cinnamon, ginger, cloves, brown sugar, milk, and ½ cup of granulated sugar. Using a whisk, mix it until smooth and pour it evenly into the baking dish.
Make the topping: in the same bowl, mix the one cup of white mix you reserved with 4 tablespoons of melted butter, ½ cup of sugar, and the chopped pecans. Sprinkle this mixture evenly on top of the cake batter.
Place the baking dish on the bottom rack of the oven and bake for one hour.
Let it rest for 30 mins, and serve warm. You can also let it cool completely, cover it with plastic wrap and refrigerate for up to 5 days. It is delicious both warm or cold.