Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.,Cream the butter and espresso grounds together until light and fluffy.,In a separate bowl, whisk together the flour, espresso, baking powder, baking soda, and salt.,In another bowl, combine the brown sugar, granulated sugar, eggs, and vanilla extract. Mix until smooth.,Gradually combine the wet and dry ingredients until a dough forms.,Fold in the chocolate chunks.,Scoop dough onto the prepared baking sheet, spacing cookies about 2 inches apart.,Bake for 10–12 minutes, until edges are golden but centers remain soft.,Immediately sprinkle with sea salt flakes and let cool on the baking sheet for 5 minutes before transferring to a wire rack.