1. Preheat oven to 325°F (165°C) and line a baking sheet with parchment paper.

2. In a mixing bowl, combine sourdough discard, flour, olive oil, and salt until a soft dough forms. Add water, 1 teaspoon at a time, if dough is too dry.

3. Lightly flour a work surface and knead the dough for 1–2 minutes until smooth. Cover and rest for 20 minutes.

4. Divide dough in half. Place one half between two sheets of parchment paper and roll very thin, about 1/16 inch thick.

5. Brush the dough lightly with olive oil and sprinkle with optional rosemary, pepper, or Parmesan. Score into crackers with a pizza cutter without separating.

6. Transfer parchment to the baking sheet and bake for 20–25 minutes, rotating halfway, until edges are golden and crisp.

7. Remove crackers from oven and immediately transfer to a cooling rack to prevent steam from softening.

8. Once completely cool, break along score lines and store in an airtight container for up to one week.

9. For make-ahead, roll and cut dough, then freeze between parchment sheets. Bake from frozen at 325°F (165°C) for 25–30 minutes.