In a large bowl, stir together the water and kosher salt until the salt dissolves.
Cut the apples into ½-inch pieces and immediately place them in the salt water. Let them soak for about 10 seconds to help prevent browning.
Drain the apples well. Reserve about one-eighth of the chopped apples in a small covered container and refrigerate them for topping later. Set the remaining apples aside.
In a large bowl, whisk together the milk and instant vanilla pudding mix until thickened, about 45 seconds.
Gently fold the Cool Whip into the pudding mixture until smooth and combined.
Fold in the remaining apples and four of the chopped Snickers bars, reserving the remaining candy pieces for topping.
Transfer the mixture to a serving bowl and refrigerate for about 1 hour, or until thoroughly chilled.
Just before serving, top with the reserved apples and remaining chopped Snickers. Drizzle generously with caramel sauce.