Step 1: Preheat your oven to 350°F (175°C) and lightly grease a 9x13-inch baking dish. This ensures a clean release and prevents any sticking.
Step 2: In a large bowl, combine the canned pumpkin puree, evaporated milk, granulated sugar, brown sugar, eggs, pumpkin pie spice, and vanilla extract. Whisk until all ingredients are well combined and the mixture is smooth. This is your luscious pumpkin base.
Step 3: Pour the pumpkin mixture evenly into your prepared 9x13-inch baking dish. Spread it out with a spatula to ensure an even layer.
Step 4: Evenly sprinkle the dry yellow cake mix over the entire pumpkin layer. Do not mix it in! The goal is a uniform, dry layer over the wet pumpkin. Try to cover every part of the pumpkin mixture.
Step 5: Drizzle the melted unsalted butter evenly over the dry cake mix. Again, avoid stirring. The butter will seep into the cake mix, creating that wonderful, buttery crust. If you notice any dry spots, try to gently nudge the butter to cover them.
Step 6: If desired, sprinkle the chopped pecans over the butter and cake mix layer. This adds an extra layer of crunch and nutty flavor, perfect for fall.
Step 7: Bake for 50-60 minutes, or until the top is golden brown and a knife inserted into the center comes out mostly clean (a little moistness from the pumpkin is fine, but it shouldn't be liquid). The edges should be set, and the center slightly jiggly.
Step 8: Remove from oven and let the Easy Pumpkin Dump Cake cool for at least 15-20 minutes before serving. This allows it to set up properly. It’s delicious warm, but also fantastic at room temperature.