01 - Preheat oven to 350°F. Generously grease a 9x13-inch baking pan.
02 - In a large mixing bowl, whisk together pumpkin puree, sweetened condensed milk, eggs, pumpkin pie spice, granulated sugar, and salt until completely smooth.
03 - Pour the blended pumpkin mixture evenly into the prepared baking pan.
04 - Evenly sprinkle the dry yellow cake mix over the pumpkin layer without mixing.
05 - Slowly drizzle the melted unsalted butter over the cake mix, ensuring coverage.
06 - Distribute chopped pecans evenly over the surface if desired.
07 - Bake for 45 to 55 minutes until the topping is golden and the center is set. The dessert will continue to firm while cooling.
08 - Allow to cool at least 30 minutes before slicing. Serve warm or chilled, with whipped cream or vanilla ice cream if preferred.