1. Preheat the oven to 350°F (175°C) and line a baking tray with parchment paper.

2. In a large bowl, cream together the softened butter, brown sugar, and granulated sugar until pale and fluffy.

3. Add the egg and vanilla extract, mixing until fully incorporated.

4. Stir in the sourdough discard until just combined, taking care not to overmix.

5. In a separate bowl, whisk together the flour, baking soda, and salt, then gently fold into the wet ingredients.

6. Fold in the chocolate chips and any optional add-ins.

7. Cover the dough and chill in the refrigerator for 30–45 minutes.

8. Roll the dough to ¼ inch thickness on a lightly floured surface and cut into hearts with a cookie cutter.

9. Place the hearts on the prepared tray, chill for 5–10 minutes, and optionally sprinkle with flaky sea salt.

10. Bake for 10–12 minutes until the edges are lightly golden and centers remain soft.

11. Let cookies rest on the tray for 5 minutes, then transfer to a cooling rack.

12. Store cooled cookies in an airtight container for up to five days or freeze dough or baked cookies as desired.