Preheat your oven to 350°F (175°C).
Cream together the sliced unsalted butter, packed brown sugar, and granulated sugar until light and fluffy (about 2-3 minutes).
Add the large egg and vanilla extract, mixing until well combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually add to the wet mixture, stirring until just combined.
Fold in the chocolate chips until evenly distributed.
Drop rounded balls of dough onto a parchment-lined baking sheet, spacing them about 2 inches apart. Top with a pinch of coarse sea salt.
Bake for 10-12 minutes, or until edges are lightly golden but centers are soft.
Cool on the baking sheet for 5 minutes before transferring to a wire rack.