cake flour (equivalent to 1 cup minus 1 Tablespoon, or 120.5 grams),
bread flour (equivalent to 1/2 cup plus 1/3 cup, or 120.5 grams),
plus 1/8 teaspoon baking soda (2.5 grams),
baking powder (3 grams),
kosher salt (4 grams),
and 1/4 sticks unsalted butter (10 Tablespoons, or 141 grams), softened,
brown sugar (1/2 cup plus 2 Tablespoons brown sugar, or 142 grams),
white sugar (1/2 cup plus 1 Tablespoon, or 113 grams),
large egg, at room temperature,
vanilla extract (10 ml),
chocolate (60% cacao, or dark chocolate) (~280 grams),
Sea salt for sprinkling (optional, but highly recommended)