Step 1

Preheat oven to 325 degrees F. Grease a 9-inch square pan and line with parchment paper; set aside.

Step 2

In a medium bowl, whisk together the flour, baking soda, and salt; set aside.

Step 3

Using an electric mixer, mix together the melted butter and sugars on medium speed until combined. Add the egg, egg yolk, and vanilla extract and mix until smooth. Slowly add the dry ingredients and mix on low, just until combined. Stir in the chocolate chips.

Step 4

In a medium microwave-safe bowl, combine the caramels and heavy cream. Microwave on high until the caramels are melted, stirring every 20 seconds. This will take about 2 minutes.

Step 5

Press half of the cookie dough into the prepared pan, smoothing the top with a spatula. Pour the hot caramel over the dough cookie dough and spread into an even layer, leaving about ½ inch around the border. Sprinkle the caramel with sea salt. Drop the remaining cookie dough in spoonfuls over the caramel and gently spread the dough with a spatula until the caramel is covered. Sprinkle the bars with additional sea salt.

Step 6

Bake for 30 minutes, or until the top of the bars are light golden brown and the edges start to pull away from the pan. Place the pan on a wire rack and cool to room temperature, then refrigerate for about 30 minutes to allow the caramel layer to set. Cut into squares and serve. Store leftovers in an airtight container at room temperature for up to 4 days.