Heat oven to 350°F. Lightly grease a 9×13-inch baking dish with vegetable oil.
Whisk pumpkin puree, evaporated milk, beaten eggs, granulated sugar, pumpkin pie spice, salt, and vanilla until smooth.
Pour the pumpkin mixture into the prepared baking dish and spread it evenly.
Sprinkle the dry cake mix evenly over the pumpkin layer. Do not stir.
Drizzle the melted butter evenly across the dry mix, covering as much surface as possible.
Scatter pecans over the top, then dust with brown sugar for extra crunch.
Bake until the top is deeply golden and the center is set, 50–55 minutes.
Cool at least 20 minutes to help it set. Serve warm or at room temperature.
Notes
Swap pecans with walnuts or skip nuts for a nut-free version. Add a caramel drizzle or a dollop of whipped cream before serving. Store leftovers covered in the fridge for up to 4 days; warm slices briefly in the microwave to revive the texture.This recipe is an original creation inspired by classic Easy Pumpkin Pie Dump Cake Recipe flavors. All ingredient ratios and instructions are independently developed.