Spray the inside of a crockpot with cooking spray or use a crockpot liner. Add the pumpkin pie mix to the prepared crockpot, and use a spatula to spread it into an even layer.
In a medium mixing bowl, combine the spice cake mix, melted butter, and ground cinnamon. Use a fork to combine the ingredients into a crumbly mixture.
Sprinkle the crumble topping evenly over the pumpkin layer in the crockpot. Top with pecans.
Before placing the lid on the crockpot, cover the insert with a dry kitchen towel (or layered paper towels). You only want to lay the towel on top—be sure that it is not touching the dessert inside. Place the lid over the towel and cook on low for 2 hours.
After two hours, remove the lid and towel. Continue to cook, uncovered, for another thirty minutes, until the topping is slightly crisp.
Turn the crockpot off , and allow the cake to cool, uncovered, for 20 minutes until the cake is set.
Serve warm and enjoy!
Notes
Leftovers can be stored in an airtight container in the refrigerator for up to three days.Reheat individual portions in the microwave at 15-second intervals until heated through.I do not recommend freezing, the cake will separate.