01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together flour, baking soda, and fine sea salt in a medium bowl.
03 - Beat butter, granulated sugar, and brown sugar in a large bowl until light and creamy, about 2 minutes.
04 - Add eggs one at a time, beating well after each addition, then mix in vanilla extract.
05 - Gradually add dry ingredients to wet mixture, mixing on low speed until just combined.
06 - Fold in dark chocolate chips and nuts if using, with a spatula.
07 - Scoop heaping tablespoons of dough onto prepared baking sheets, spacing about 2 inches apart.
08 - Sprinkle each cookie with a pinch of flaky sea salt.
09 - Bake for 11 to 13 minutes until edges are golden but centers remain soft.
10 - Let cookies cool on baking sheet for 5 minutes, then transfer to wire rack to cool completely.