Preheat oven to 350 degrees F (180 degrees C). Grease or spray a baking dish that is  9x13 inch 

In a large bowl, mix pumpkin, evaporated milk, eggs, sugar, pumpkin pie spice, and salt. 

Using a hand mixer, mix well, and pour evenly into the baking pan. But be careful! Pumpkin has a high spatter so you might want to use an immersion blender instead of the hand mixer.

Spread the filling evenly with a spatula or knife, especially into the corners. 

Using a dessert (large spoon) carefully sprinkle the butter pecan cake mix over the pumpkin filling, making sure to get into the corners.

Level the cake mix on the filling using the back of your spoon. Sprinkle chopped pecans or pecan pieces evenly over the cake mix.

The final step is to drizzle the melted butter all over the top using a large spoon. The melted butter will cover the entire cake.

Bake for 60 minutes at first and then add time depending on your oven. If you stick a straw or toothpick into the cake topping it should come out clean.

Refrigerate until ready to serve.

Serve with a scoop of your fave vanilla ice cream or whipped topping like Cool Whip!