01 - Preheat oven to 350°F. 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 smooth.
03 - Pour pumpkin mixture evenly into prepared baking pan.
04 - Sprinkle the dry yellow cake mix evenly over the pumpkin layer without stirring.
05 - Drizzle melted butter evenly over the dry cake mix, ensuring all areas are moistened.
06 - Scatter chopped pecans over the surface if using.
07 - Bake in preheated oven for 45 to 55 minutes, until the top is golden brown and the center is set.
08 - Allow to cool for at least 30 minutes before serving. Enjoy warm or chilled, optionally with whipped cream or vanilla ice cream.