Created by medgirl42 on June 15, 2013
Step 1: Sift flours, baking soda, baking powder and kosher salt into a bowl. Set aside.
Step 2: Using a mixer fitted with paddle attachment, cream butter and sugars together until very light, about 5 minutes.
Step 3: Add eggs, one at a time, mixing well after each addition.
Step 4: Stir in the vanilla. Reduce speed to low, add dry ingredients and mix until just combined, 5 to 10 seconds.
Step 5: Drop chocolate pieces in and incorporate them without breaking them.
Step 6: Press plastic wrap against dough and refrigerate for 24 to 36 hours. Dough may be used in batches, and can be refrigerated for up to 72 hours.
Step 7: When ready to bake, preheat oven to 350°.
Step 8: Line a baking sheet with parchment paper or a nonstick baking mat. Set aside.
Step 9: Scoop six 3 1/2-ounce mounds of dough (the size of generous golf balls) onto baking sheet, making sure to turn horizontally any chocolate pieces that are poking up; it will make for a more attractive cookie.
Step 10: Sprinkle lightly with sea salt and bake until golden brown but still soft, 18 to 20 minutes.
Step 11: Transfer sheet to a wire rack for 10 minutes, then slip cookies onto another rack to cool a bit more. Repeat with remaining dough, or reserve dough, refrigerated, for baking remaining batches the next day.
Step 12: Best when eaten warm.