Do not over-mix the batter to achieve a soft and chewy cookie. Mix until "just incorporated" after each ingredient addition to avoid adding air, which creates a cake-like cookie.
Bread flour produces a chewier cookie due to its higher gluten content; all-purpose flour can be substituted but will result in a less chewy cookie.
Enhance flavor with a pinch of flaked sea salt on top of dough balls before baking.
Store baked cookies at room temperature in an airtight container for up to 7 days, placing a small piece of white bread in the container to keep them extra fresh and chewy.
Freeze leftover baked cookies individually wrapped in plastic wrap and stored in a freezer-safe bag for up to 3 months.
Unbaked cookie dough can be stored in the fridge, tightly covered, for up to 7 days.
To freeze unbaked cookie dough, portion onto a parchment-lined baking sheet, freeze, then transfer to a freezer-safe container for up to 3 months. Bake frozen dough at 375°F (190°C) for 17-20 minutes, or thaw overnight in the fridge and bake as directed.