Preheat oven to 375°F. Line 2 baking pans with parchment paper and set aside.
In the mixing bowl, add flour, baking soda, and baking powder. Use a whisk to combine. Set aside.
In a separate mixing bowl, add unsalted butter at room temperature, granulated white sugar, and brown sugar.
Using a pedal attachment, beat until pale and smooth. About 2-3 minutes.
Add egg and beat until combined.
Sift in dry ingredients and mix until combined.
Add chocolate chips or chopped chocolate and mix well.
Roll 2-3 tablespoons (depending on how large you like cookies) of dough at a time into balls and place them on prepared cookie sheets.
Add more chocolate chips on top of cookies (optional).
Bake cookies in a preheated oven for 8-10 minutes.
Once baked and the cookies are still warm, top them with chopped chocolate.
Sprinkle flakes of sea salt on top of the cookies.
Let cookies sit on the baking pan for a few minutes. Then, remove the cookies from the cooling rack.
Notes
Get all ingredients and tools ready before baking. Measure all ingredients by weight using a kitchen scale. All ingredients should be at room temperature.