1–1/2 cups dark or semi-sweet chocolate chips or chopped chocolate, plus extra for topping
Flaky sea salt for garnish (optional)
Instructions
Melt butter in a light-colored saucepan over medium heat. Stir and swirl occasionally until it foams, turns golden brown, and smells nutty, about 5-7 minutes. Scrape all browned bits into a large mixing bowl. Cool for 10-15 minutes.
Add brown sugar and granulated sugar to cooled brown butter and whisk vigorously for 1 minute until smooth and slightly lighter.
Add egg, egg yolk, and vanilla extract. Whisk until smooth, glossy, and emulsified, about 30-45 seconds.
Stir in sourdough discard until fully incorporated into wet ingredients.
In a separate bowl, whisk together flour, baking soda, baking powder, salt, and cinnamon until evenly combined.
Add dry ingredients to wet ingredients. Stir with spatula or wooden spoon until just combined with no flour streaks. Avoid overmixing.
Fold in chocolate chips until evenly distributed. Save extra chips for topping.
Cover bowl tightly with plastic wrap and refrigerate for at least 2 hours, preferably overnight or up to 72 hours. This step is essential for thick cookies.
Preheat oven to 350°F and line baking sheets with parchment paper. Let dough sit at room temperature for 5-10 minutes if very firm.
Scoop dough into 2-tablespoon-sized balls and place 2 inches apart on prepared baking sheets.
Bake for 10-12 minutes until edges are golden and centers still look slightly soft.
Immediately press extra chocolate chips on top. Use large round cookie cutter or glass to gently push edges inward for perfect circles if desired.
Cool on baking sheet for 5 minutes, then transfer to wire rack. Sprinkle with flaky sea salt while warm if using. Cool completely, about 20 minutes.
Notes
European-style butter creates the best brown butter flavor. Unfed sourdough discard gives the most tangy flavor.
Watch butter carefully when browning – it can burn quickly. Chilling is essential for thick, bakery-style cookies.
Freeze baked cookies or dough balls for up to 3 months. Bake frozen dough balls with 1-2 extra minutes.