01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan thoroughly.
02 - In a large mixing bowl, whisk together pumpkin puree, sweetened condensed milk, eggs, pumpkin pie spice, granulated sugar, and salt until uniform in texture.
03 - Pour pumpkin mixture into the prepared pan, spreading evenly across the base.
04 - Distribute the dry yellow cake mix evenly over the pumpkin layer, ensuring complete coverage without mixing.
05 - Drizzle melted butter evenly over the cake mix layer, covering as much surface as possible. Scatter chopped pecans on top if desired.
06 - Bake for 45 to 55 minutes, or until the surface is golden brown and the center is set. The dessert will firm up upon cooling.
07 - Allow to cool for at least 30 minutes before serving. Plate warm or chilled, optionally garnished with whipped cream or vanilla ice cream.