Preheat your oven to 350°F (175°C). Grease the 9x13 inch baking dish.
In a mixing bowl, combine the pumpkin puree, evaporated milk, eggs, sugar, vanilla extract, cinnamon, nutmeg, ginger, and salt. Whisk together until well blended.
Pour the pumpkin mixture into the prepared baking dish, spreading it evenly.
Sprinkle the dry cake mix evenly over the pumpkin mixture. Do not mix, just let it rest on top.
Combine the chopped pecans and melted butter in a separate bowl. Stir until the pecans are well coated.
Sprinkle the pecan mixture evenly over the cake mix layer.
Bake in the preheated oven for 50 minutes, or until the edges are set and the center is slightly jiggly.
Allow the cake to cool for at least 20 minutes before serving. Serve warm or at room temperature with whipped cream on top.