Preheat the oven to 350°F (177°C) and place racks in the middle position. Line baking sheets with parchment paper or a silicone mat.

In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

In a large bowl, cream the softened butter with both sugars until the mixture is light and fluffy, about 2 to 3 minutes. Use a stand mixer or hand mixer on medium speed.

Add the eggs one at a time, mixing each until combined. Stir in the vanilla. Scrape the bowl as needed.

Add the dry ingredients in two additions, mixing on low speed until no dry streaks remain. Stop as soon as the flour is incorporated to avoid overmixing.

Fold in the chocolate chips and nuts (if using) with a spatula so the chips stay intact.

Chill the dough for 30 minutes for thicker cookies, or up to 24 hours in the refrigerator for deeper flavor and even more chew.

Scoop 2-tablespoon portions of dough and place them on the prepared baking sheet, leaving about 2 inches between each.

Bake for 10 to 12 minutes. Look for golden edges and centers that still look slightly soft. Rotate the pan halfway through baking for even color.

Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely.

Sprinkle flaky sea salt on top while warm if you like a salty-sweet finish.