• Line a baking sheet with parchment paper. Set aside.

Prepare Dry Mixture

• In a small bowl, whisk together flour, baking soda, cornstarch and salt. Set aside.

Dough Making

• Prepare your wet mixture by using a large bowl with an electric mixer or the bowl of a stand mixer, to beat sugars (brown and granulated) with melted butter. Add in egg and vanilla extract. Mix until smooth (~1 min). Scrape sides of bowl to incorporate all the batter.
• Slowly add flour mixture to the wet butter/sugar/egg mixture, beating on low speed until just combined. Add roughly chopped chocolate pieces to the batter. Mix until chocolate speckles dough (only a few seconds).
• Scoop dough into 3 tbsp portions and set on flat plate/baking sheet.
• Refrigerate dough for at least 30 min (ideally 1h).
• Preheat oven to 350F (325F if using convection bake).
• Once dough is chilled, remove from fridge and place cookies onto baking sheet, spaced 2-3" apart (note: I have 4-5 cookies on a baking sheet, at a time).
• Bake cookies at 350F for ~12 min or until the edges are golden brown. Immediately take a round cookie cutter (or cup/bowl) big enough to fit over cookie and use it to shape cookie into perfect circle.
• Sprinkle each cookie with flaked salt and allow them to cool completely on the baking sheet.
• Enjoy!