Step 1

Preheat your oven to 375F (190C). Make sure you have a rack in the top third of your oven (allow at least six inches (15cm) from the heat source). Line several baking sheets with parchment paper.

Step 2

In an electric stand mixer fitted with the paddle attachment, cream your brown sugar, butter, oil and granulated sugar on medium speed for about 5 minutes or until fully incorporated, light and creamy. Add the eggs, one at a time, making sure each is well blended before adding the next. Add the vanilla and mix on medium until everything is well blended. Take the bowl out of the mixer.

Step 3

In a medium bowl whisk together the all-purpose flour, bread flour, baking powder, baking soda and sea salt. Add the flour mixture to the wet ingredients and fold until the cookie dough is barely blended and you still see streaks of flour. Add the chocolate chunks and fold until just mixed.

Step 4

Gently roll 2 tablespoon-sized balls, place on the prepared baking sheet and allow about 2 inches (5 cm) of space between the dough balls. Bake the cookies in the top third of the oven for about 11 minutes. They will look slightly underdone. Fresh out of the oven, sprinkle with the sea salt flakes, if using. Allow to cool on the baking sheet for 5 minutes and then transfer to a rack to finish cooling.