1. Brown the butter in a light-colored saucepan over medium heat, stirring until golden brown and fragrant, then pour into a heatproof bowl and cool for 10–15 minutes

2. Whisk the cooled brown butter with brown sugar and granulated sugar until smooth and combined

3. Add the egg and vanilla extract and whisk until glossy, then stir in the sourdough discard until the mixture is smooth

4. In a separate bowl, sift together the flour, baking soda, and salt, then gently fold the dry ingredients into the wet mixture until no streaks of flour remain

5. Fold in the dark chocolate chips and dried cranberries, and nuts if using, distributing them evenly throughout the dough

6. Cover the dough and chill in the refrigerator for at least 30 minutes to firm up and develop flavor

7. Preheat the oven to 350°F (175°C) and line baking sheets with parchment paper

8. Portion the chilled dough into 1½ tablespoon-sized balls and place them 2 inches apart on the prepared sheets

9. Bake for 10–12 minutes until the edges are golden brown and the centers are just set, then let the cookies rest on the baking sheet for 5 minutes before transferring to a wire rack to cool completely

10. Store cooled cookies in an airtight container at room temperature for up to 4 days, refrigerate for up to 1 week, or freeze dough balls or baked cookies for longer storage