In a stand mixer with paddle attachment, cream butter and both sugars on medium-high speed for 5 minutes until pale and fluffy.

Aeration creates lift—don't shortcut this step • Mixture has increased in volume, looks whipped

Add eggs one at a time, beating well after each addition. Add vanilla. Mix until smooth.

Add eggs slowly to prevent breaking the emulsion • No streaks of egg visible

In a separate bowl, whisk together both flours, baking soda (1¼ tsp), baking powder (1¼ tsp), and salt. Add dry ingredients to butter mixture. Mix on low speed just until no white flour is visible. Do not overmix.

Stop the second you see no more white flour—overmixing creates tough cookies • Dough looks shaggy, slightly lumpy

Add chocolate discs. Fold in by hand with a spatula until evenly distributed.

Hand folding is gentler than mixer • Chocolate pieces throughout dough

Wrap dough tightly in plastic wrap. Refrigerate for at least 24 hours, ideally 36 hours.

This is where flavor happens—flour hydrates, starches break down into sugars • Dough looks drier on surface, darker • Richer, toffee-like aroma

Preheat oven to 350°F (175°C). Scoop dough into large golf ball-sized portions (about 3 tbsp each). Place on parchment-lined baking sheets, 3 inches apart.

Bake straight from fridge—cold dough spreads less • Large, round balls spaced far apart

Sprinkle each dough ball generously with flaky sea salt (2 tbsp).

Salt is structural, not optional—it balances sweetness • White salt crystals on dough surface

Bake for 12-15 minutes. Edges should be crispy brown, centers should look slightly underdone and pale. They will look too soft but will set as they cool.

Pull them early—they keep cooking from carryover heat • Golden brown edges, pale centers • Toasted butter aroma

Let cool on baking sheet for 5 minutes, then transfer to a wire rack. They will firm up as they cool.

Don't skip the rest—they're too fragile hot • Edges are crispy, centers are chewy