Preheat oven to 350°F. Coat a 13- x 9-inch baking dish with cooking spray. Gather all ingredients.
Whisk together eggs, corn syrup, brown sugar, cream, vanilla, and ½ cup of the butter until smooth. Stir in 2 cups of the pecans until well coated. Transfer mixture to prepared baking dish.
Sprinkle cake mix and pumpkin pie spice evenly over pecan mixture. Drizzle evenly with remaining ½ cup butter and sprinkle with remaining 1 ½ cups pecans.
Bake in preheated oven for 20 minutes. Cover with aluminum foil and bake until lightly golden brown and no dry spots remain on top, about 20 minutes longer. Let cool at least 15 minutes before serving warm or at room temperature with ice cream and caramel, if desired.
