In a bowl, combine the two flours, baking soda, baking powder, corn starch and salt.
Add in the chocolate and mix carefully with spatula.
Cover the dough with plastic wrap as if it was a guacamole. Letting air get to the dough will dry it out in a bad way.
Refrigerate for 36 hours.
Preheat your oven to 175C or 350F.
Sprinkle the tops with sea salt.