Preheat oven to 325 degrees F. Grease a 9-inch square, brownie pan and set aside
In a medium bowl, mix together the flour, baking soda, and regular salt; set aside.
Mix together the melted butter and sugars on medium speed until combined. Add the egg, egg yolk, vanilla extract, Brandy, coffee powder and mix until smooth. Add slowly the dry ingredients and mix on low, just until combined. Stir in the chocolate chips.
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.
Press half of the cookie dough into the pan, smoothing the top. Pour the hot caramel over the cookie dough and spread into an even layer, leaving some empty space around the edges. Sprinkle the caramel with Fleu-de-sel. Drop the remaining cookie dough over the caramel and gently spread the dough with a spatula until the caramel is covered. Sprinkle the bars with additional sea salt.
Bake the cookie bars for 30 minutes, or until the top of the bars are light golden brown. Cool the bars on a wire rack 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.