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

2. Beat the butter, brown sugar, and granulated sugar until light and creamy

3. Stir in the sourdough discard, egg, and vanilla extract until smooth

4. Whisk together the flour, baking soda, and salt and fold into the wet ingredients until just combined

5. Fold in the chocolate chips and chill the dough for at least 1 hour

6. Roll out the chilled dough to 1/2 inch thickness on a lightly floured surface

7. Cut dough with a heart-shaped cookie cutter and place cookies 2 inches apart on the prepared baking sheet

8. Bake for 10 to 12 minutes until edges are golden

9. Remove from the oven and sprinkle with flaky sea salt if desired

10. Let cookies cool on the baking sheet for 5 minutes then transfer to a wire rack to cool completely