In a medium bowl, whisk together the flour, baking soda, and sea salt. Set the bowl aside for a few minutes.
In a separate large mixing bowl, using a handheld mixer on low speed, beat the melted butter, brown sugar, and granulated sugar together until incorporated and lump-free. Add the egg, egg yolk, and vanilla extract and mix on low until incorporated.
Add the flour mixture in several increments while mixing on low. Scrap down the side of the bowl when needed. Mix just until combined. Remove the mixer and, using a spoon, stir in the chocolate chips.
Cover and refrigerate for about 3 hours.
Preheat the oven to 325 degrees. Cover a baking sheet with parchment paper.
Use a 1 1/2 tablespoon scoop to place the cookie dough balls on the prepared baking sheet with at least 2 inches between the dough balls. Bake for 12-13 minutes or until lightly browned. Remove from the oven and cool for 5 minutes before moving the cookies to a wire rack to cool.
Measure the flour correctly by spooning it into a measuring cup and then leveling it off with a kitchen knife.
For best results, use parchment paper or a silicone baking mat. It promotes even baking and browning, reduces spreading, and eliminates sticking.
Preheat your oven and load the cookies on the middle rack in the center of the oven. Use two baking sheets and alternate them. Do not place cookie dough balls on a hot sheet.
If desired, add 2/3 cup chopped walnuts or pecans at the same time as the chocolate chips.
Leave 2-2 1/2 inches between each dough ball for spread and so the heat circulates well between the cookies.
For an over-the-top presentation, gently press a few chocolate chips into the tops of the cookies as soon as they come out of the oven.
Last but not least, and perhaps the most important tip of all. Bake a few cookies off on a test run. If they spread too fast, refrigerate the dough for 1-2 hours and test again. If they do not spread enough, gently press the rounded spoonfuls of dough down with the palm of your hand and test again.
