Step 1: Begin by preheating your oven to 350°F (175°C). Then, lightly grease a 9x13-inch baking dish.
Step 2: In a large mixing bowl, combine your 100% canned pumpkin puree with evaporated milk, granulated sugar, light brown sugar, eggs, pumpkin pie spice, and pure vanilla extract. Whisk all ingredients until thoroughly combined and smooth.
Step 3: Carefully pour the pumpkin mixture evenly into your prepared 9x13-inch baking dish. Use a spatula to gently spread it out, ensuring a uniform layer.
Step 4: Evenly sprinkle the entire contents of the dry yellow cake mix over the pumpkin layer. Vital: do NOT mix it in! The goal is a uniform, dry layer over the wet pumpkin mixture, covering every part.
Step 5: Gently drizzle the melted unsalted butter evenly over the dry cake mix. Resist the urge to stir! The butter will seep into the cake mix as it bakes, working its magic to create that wonderful, buttery, and slightly crunchy crust. If you notice any dry spots, gently nudge the butter to cover them, ensuring even caramelization and texture.
Step 6: If you’re a fan of extra crunch and nutty depth, sprinkle chopped pecans evenly over the butter and cake mix layer. This addition is optional but adds fantastic textural contrast and lovely autumnal flavor.
Step 7: Place your baking dish into the preheated oven. Bake for approximately 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 layer is fine, but it should not be liquid. The edges should be set, and the center might have a slight jiggle.
Step 8: Once baked, remove the Easy Pumpkin Dump Cake from the oven and let it cool for at least 15-20 minutes before serving. This cooling time allows the cake to set properly, making it easier to serve. It’s delicious warm, but also fantastic at room temperature.