Preheat oven to 350°F (175°C) and line two baking sheets with parchment paper.
In a medium bowl, whisk together flour, baking soda, and salt.
In a separate large bowl, whisk melted butter with brown sugar and white sugar until smooth and glossy.
Add egg, egg yolk, and vanilla. Whisk until creamy.
Gradually mix in the dry ingredients until a soft dough forms.
Fold in caramel pieces and chocolate chips.
Scoop dough balls onto the baking sheet, spacing them 2 inches apart.
Bake for 10–12 minutes, until edges are golden and centers are soft.
Sprinkle lightly with flaky sea salt while warm.
Cool on the tray for 5 minutes before transferring to a wire rack.