In a large bowl, combine graham cracker crumbs with butter and sugar. Mix well.
Press graham cracker mixture into the bottom of a greased 9x13" pan. Bake for 10 minutes. Remove from oven. Allow to cool completely before continuing with the next step.
In a large bowl, whisk pudding, milk, pumpkin puree and pumpkin pie spice together until thickened. Then fold in one cup of Cool Whip. Spread the pumpkin mixture over the cooled graham cracker crust.
Spread remaining Cool Whip over pumpkin layer. Then lightly dust the top with remaining graham cracker crumbs, sprinkle with chopped pecans and drizzle on the chilled caramel syrup over top.
Cover with aluminum foil. Chill in the refrigerator for at least four hours before serving.
Calorie count accounts for using 1/4 cup of sundae caramel syrup. However you're welcome to use more or less to taste.Use a food processor to get a really good crumb consistency from the graham crackers. If you don't have one, place the graham crackers in a bag and roll over it with a rolling pin, but it's not as efficient as a food processor. You can also use your blender by crushing them in very small batches so it doesn't gum up the blade.Be sure to let the crust cool down a few minutes before you start adding layers to the dessert.It's important to use an instant pudding instead of a cook and serve variety. This is going to yield a very fast prep time. Otherwise, you'll be cooking it on the stove for an extended time.Thaw out the whipped cream before you add that layer to the pumpkin dessert. It will last around 3-5 days in the refrigerator. You can substitute Golden Oreos, Ginger Snaps or nuts into the graham crackers for crust variations.