In the bowl of a stand mixer fitted with a paddle attachment, cream the butter, brown sugar, and granulated sugar on medium speed until they are smooth, about 1 minute.
Add the vanilla and egg to the butter mixture and mix on medium speed until they are fully incorporated, scraping down the sides of the bowl as needed.
In a medium bowl, whisk together the flour, salt, baking powder, and baking soda. With the mixer on low speed, add the flour mixture in two batches to the butter mixture, and mix until the ingredients are just combined, about 1 minute.
Separate the chopped chocolates into two portions; I like to reserve the larger pieces to top each cookie dough ball before baking. Add one portion of the chocolates to the bowl, and mix until they are just incorporated with the dough, about 30 seconds. Set second portion of chocolates aside.
Preheat the oven to 350°F (177°C). Line a large baking sheet with parchment paper.
With a standard ice cream scoop, form balls of dough and place them about 2 inches (5 cm) apart on the baking sheet. Place several pieces of reserved chocolate onto each dough ball.
Bake the cookies for 12 to 14 minutes, or until the cookies are browned and caramelized along the edges and the centres are just set. If you would like your cookies to have the crinkled edges, give the pan a few taps on the oven rack before you take them out of the oven.
Top each cookie with a sprinkling of the Maldon sea salt flakes. Allow the cookies to cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely.
The cookie dough freezes really well. After portioning the dough into dough balls, you can freeze the dough balls to be baked off at a later date. If you feel like you only want six cookies today, save the other six dough balls for next week. Future you will thank the present you.
My Favourite Chocolate Chip Cookies by Amy of Constellation Inspiration