Preheat oven to 350F. Line a 9×13-inch pan with aluminum foil and spray with cooking spray; set aside.
Make cake according to package directions (likely adding 3 eggs, water, and oil) and bake as directed (I find my cakes are done about 3 to 5 minutes faster than the box directions and if baked as long as indicated, I find the cake is too dry but bake as necessary).
While the cake bakes add the sweetened condensed milk and caramel topping to a medium bowl and stir to combine; set aside.
Remove cake from the oven when it’s done and using the blunt end of a wooden spoon, poke holes over the surface of the cake. I didn’t count but I estimate I poked about 60 holes, evenly spaced over the surface.
Slowly pour the sweetened condensed milk and caramel mixture over the holes, taking your time to evenly distribute it so that all the holes receive some. Place cake in the fridge for about 10 minutes to cool slightly before adding the whipped topping so it doesn’t melt.
Remove cake from the fridge, evenly spread the whipped topping over the surface, evenly sprinkle the pecans and chocolate chips, cover cake, and refrigerate for at least 2 hours (overnight is best).
Evenly drizzle the salted caramel sauce before slicing and serving. Cake will keep airtight in the fridge for up to 5 days.