Preheat the oven to 350°F. Line the bottom of a 9x13 baking dish with parchment paper and spray the bottom and sides with non-stick cooking spray.
Beat together the softened butter, granulated sugar, and brown sugar in the bowl of a standing mixer for 1 to 2 minutes.
Add the eggs and vanilla extract then beat together at high speed for at least 5 minutes longer.
Mix together the flour, ½ teaspoon sea salt, and baking soda in a small bowl. Add to the creamed mixture and beat just until combined.
Add in 2 cups of chocolate chips and beat a few seconds longer to evenly distribute them in the dough.
Place the dough into the refrigerator while preparing the caramel (this will firm the dough up a bit to make it easier to press into the pan).
Unwrap all of the caramel candies and place them in a heavy-bottomed saucepan. Pour sweetened condensed milk over the caramels. Heat over medium-low, stirring frequently until caramels are fully melted, and the mixture is smooth (about 8 to 10 minutes). Remove from heat.
Add ½ teaspoon of sea salt flakes and stir into the caramel mixture.
Press half of the cookie dough into the bottom of the prepared 9x13 pan. If the dough is too sticky, use a spatula or a sheet of plastic wrap to press down the cookie dough layer.
Spread the caramel mixture in an even layer over the cookie dough base.
Sprinkle the other half of the cookie dough mixture in small pieces over the caramel layer, covering most of the surface.
Bake for 25 minutes or until the center of the cookie dough is set.
Remove from the oven and sprinkle with another ½ to 1 teaspoon of sea salt flakes.
Cool completely then cut into bars and serve.
Notes
Lining the pan with overhanging parchment paper will make cleaning up a snap and lifting these scrumptious bars out of the pan to cut into squares much easier.
The exact amount of salt depends entirely on how salty you want your salted caramel to be. I advise adding the salt gradually – you can always add more, but cannot take it away!