Preheat oven to 350°F. Grease a 13×9 pan.
In a bowl, beat cake mix, pumpkin, eggs, milk, oil, pumpkin spice, and cinnamon until smooth.
Pour into prepared pan; bake ~30 minutes or until a toothpick comes out clean. Let cool slightly.
Use the back of a wooden spoon or straw to poke holes about every inch across the cake.
Pour sweetened condensed milk evenly over cake, letting it sink into holes. Pour salted caramel over top.
In another bowl, mix Cool Whip and instant pudding mix until combined; spread over top.
Sprinkle the crushed gingersnap cookies evenly over the creamy topping.
Chill for at least 2 hours or overnight until set.
Cut into slices and serve.