Here's the recipe from mixandmatchmama's blog:
For some reason, salt, caramel and chocolate just go together. Perfectly.
The little bit of salt brings out the flavors of the caramel and chocolate...it doesn't make it salty, it makes it flippin' fabulous! This bar will rock your world. Rock it.
1 box chocolate cake mix
1 stick melted butter
1 box powdered sugar (about 4 cups)
1 (8 oz) cream cheese (at room temperature)
1/2 cup caramel topping (the kind you use for ice cream sundaes)
1 tablespoon Kosher or Sea Salt, divided (don't use basic table salt, get a good Kosher or Sea Salt!)
1/2 cup semi-sweet chocolate chips
Preheat oven to 350 degrees
Grease a 9x13 inch casserole dish (I always use Pam).
In one bowl, combine one box of any chocolate cake mix, two eggs and 1 stick of melted butter.
Spread mixture into prepared dish (this will be your "crust" on the bottom).
In a separate bowl, mix with a hand mixer, one box of powdered sugar, cream cheese, remaining 2 eggs, caramel topping and 1/2 tablespoon of salt until smooth. Stir in chocolate chips. Spread on top of crust mixture.
Bake 38-40 minutes.
The center of your bars will be a little wobbly when you pull it out of the oven (it won't be completely set like a cake). At this point, sprinkle your remaining 1/2 tablespoon of salt down over the warm bars. Let it cool on the counter for 30 minutes before sticking it in the fridge for at least 2 hours (or up to 2 days).
Cut into bars and serve.
You will love, love, love this sophisticated twist on a chocolate bar. Happy eating!