Preheat the oven to to 350°F. Grease a 9x13-inch baking dish. Set it aside for later.
Get a large mixing bowl. Combine the yellow cake mix, pumpkin puree, brown sugar, and pumpkin pie spice. You'll want to mix until you get a smooth consistency.
Pour the batter into the baking dish. Be sure to spread it evenly. Then, put the tray in the oven for about 25 minutes.
Test with a toothpick. When it comes out clean, the cake is ready.
After taking the cake out of the oven, let it cool off for about 15 minutes.
Once it has, take a wooden spoon and holding it by the spoon end, poke holes in the cake.
You want to make sure they're deep but don't go all the way through. Halfway is fine. Space the holes about an inch apart.
Take the sweetened condensed milk and pour it over the cake, making sure that it gets down into the holes. This is what will really make the cake taste rich and decadent.
Place the cake in the refrigerator for about 30 minutes. This gives it time to absorb the sweetened condensed milk.
Remove the cake from the fridge. Then spread the whipped topping over it, taking care to apply it smoothly and evenly.
Sprinkle the chopped pecans across the top of the cake. Don't forget the caramel drizzle!
Put the dessert back in the fridge for at least 3 hours.
Ideally you'd keep it in there overnight so that all of the flavors can fully combine. Slice and serve according to your needs and try to control the sweet tooth frenzy!