Step 1

Sift the cake flour, bread flour, baking soda, baking powder, and coarse salt into a large bowl. Set aside.

Step 2

Add the butter, brown sugar, and granulated sugar to the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer). Beat on medium-high speed until the mixture is light and fluffy, about 5 minutes. Scrape down the sides of the bowl as needed.

Step 3

Add the eggs one at a time, beating until each is fully incorporated before adding the next. Stir in the vanilla extract.

Step 4

Reduce the mixer speed to low and gradually add the dry ingredients. Mix until just combined, about 5-10 seconds. Do not overmix.

Step 5

Gently fold the chocolate discs or féves into the dough with a spatula. Be careful not to break them.

Step 6

Cover the dough with plastic wrap, pressing it directly against the surface to prevent air exposure. Refrigerate for at least 24 hours and up to 72 hours. This resting period is crucial for developing the cookies' flavor and texture.

Step 7

When ready to bake, preheat the oven to 350°Fahrenheit (175°Celsius). Line a baking sheet with parchment paper or a silicone baking mat.

Step 8

Use a kitchen scale to scoop 3 1/2-ounce portions of dough (about the size of a golf ball). Place them on the prepared baking sheet, spacing them at least 3 inches apart. For smaller cookies, scoop 1 3/4-ounce portions. Turn any protruding chocolate discs horizontally to ensure even melting.

Step 9

Lightly sprinkle the tops of the cookies with flaky sea salt. Bake for 18-20 minutes for large cookies or 10-12 minutes for smaller ones. They’re ready when the edges are golden brown, but the centers are still soft.

Step 10

Let the cookies cool on the baking sheet for 10 minutes. Then, transfer them to a wire rack to cool completely. Enjoy them warm or at room temperature!