Melt the butter in a large glass bowl. Add the sugars and whisk for about 2 minutes, or until smooth. Whisk in the eggs and vanilla.
In a small bowl, whisk together the flour, soda, and salt. Add to the wet ingredients with the chocolate chips and chocolate chunks. Stir just until combined. (I like to reserve some of the chocolate for the tops of the cookies.)
Cover the dough and chill for at least 2 hours, but up to 48 hours.
Take the dough out of the fridge and let it sit at room temperature while you preheat your oven to 350°. Line cookie sheets with silicone liner or use cooking spray.
Use 1/4 cup to portion the dough, then roll into balls. Place cookie dough balls on a prepared cookie sheet at least 3 inches apart.
Bake cookies at 350 degrees for 12-15 minutes, or until the edges are starting to turn golden brown and the middle is barely set.
Immediately press a few chocolate chips and chocolate chunks on top of each cookie. If desired, sprinkle the cookies with a bit of flaky salt. Transfer to a cooling rack to cool completely.
Notes
Cookies can be stored in an airtight container at room temperature for 4-5 days. They can also be frozen for 5-6 months. For maximum freshness, wrap individually in plastic wrap.
You can make smaller cookies, just decrease the baking time.
If you double the recipe, use 3 eggs and an egg yolk instead of 4 eggs. Details are in the post.