1 ½tubswhipped topping, thawed (About 12 oz by weight)
Instructions
Grease a 9x13 inch baking dish. For a higher ratio of filling to graham crackers you can use a dish that's slightly smaller and use fewer graham crackers.
Combine pudding mix, evaporated milk, pumpkin and pumpkin pie spice in large mixer bowl; Beat with a handheld mixer or a whisk for 2 minutes. Mixture will thicken slightly. Fold in 2 cups (about ⅔ of a tube) of whipped topping. Set filling aside.
Scrape dulce de leche into a microwave-safe bowl. Heat on high 15 seconds to soften, then spread a thin layer of dulce de leche over 16 graham crackers. Lay the dulce de leche covered graham crackers in the baking pan or dish. If they don't fit perfectly, just break them up a bit.
Spread half of the pumpkin mixture over the graham crackers, then add a second layer of graham crackers over the pumpkin mixture. I recommend leaving dulce de leche off the second layer and using them only on that one bottom layer.
Spread the remaining pumpkin mixture over the graham crackers, then top with a final layer of graham crackers. Spread remaining whipped topping over the top.
Garnish top with graham cracker crumbs and a little bit of pumpkin pie spice.
Cover and chill for about 4 to 6 hours to soften graham crackers. If you start later in the day you can chill overnight. The longer it sits, the softer the graham crackers get.