Add pumpkin, eggs, evaporated milk, sugar, and pumpkin pie spice to a large bowl.
Whisk until well-combined.
Pour into an ungreased 9x13-inch baking pan.
Sprinkle the dry cake mix over the top of the pumpkin mixture.
Pour the butter over the top of the cake mix.
Sprinkle the nuts over the top.
Bake for 60 minutes.
Serve warm or at room temperature.
Notes
Pumpkin puree: Be sure to use pumpkin puree, not pumpkin pie mix.
Evaporated milk: You can use skim, 2%, or regular evaporated milk in this recipe. Be sure to use evaporated milk, not sweetened condensed milk.
Pumpkin pie spice: You can make your own pumpkin pie spice blend with this recipe. Also, the pumpkin layer is lightly spiced. Feel free to increase the amount of pumpkin pie spice.
Yellow cake mix: You can use a yellow cake mix, golden cake mix, or a butter cake mix in this recipe. Or you can make your own cake mix with this recipe.
Butter: I use salted butter in this recipe.
Nuts: You can use walnuts, if you prefer. You can also omit the nuts.