Preheat oven to 350°F and set aside a 9x13-inch baking dish.
Mix together the pumpkin, milk, eggs, sugar, and spices and pour it into the baking dish.
Evenly sprinkle the dry yellow cake mix over the top of the pumpkin puree mixture. I like to sprinkle mine with a little extra pumpkin pie spice after the cake mix has been added.
Melt the butter and pour over the cake mix or cut the butter into thin slices and evenly distribute to cover the top of the cake with them.
Finally, spread the nuts evenly over the top of the cake. Bake for 1 hour.
Serve warm with ice cream, whipped cream, and a dash of pumpkin spice.