Preheat your oven to 325°F (165°C) and line a baking sheet with parchment paper.
Add the sourdough discard to a medium mixing bowl. Sprinkle in the fine salt, onion powder, and garlic powder, then add in olive oil or melted butter.
Stir everything together until smooth. The mixture should resemble a thick pancake batter. If it’s too thick to spread, add water one teaspoon at a time until you reach a thick but spreadable consistency.
Pour the batter onto the center of your prepared baking sheet and spread it as thinly as possible using the back of a spoon or a spatula—almost see-through in some spots. Thin batter is key for crispy crackers.
Bake for about 10 minutes, until the surface looks dry and set but not fully browned.
Remove the tray from the oven and use a pizza cutter or a knife to score the dough into cracker shapes, such as squares or diamonds.
Return the tray to the oven and bake for another 10–15 minutes, until the crackers are deep golden and fully dry in the center. To check for doneness, tap a cracker with your fingernail—it should feel crisp, not soft.
The edges usually brown faster, so remove those crackers first. Then return the tray to the oven for a few more minutes so the center crackers can finish crisping up evenly.
Once fully cooled, break the crackers apart. They will continue to crisp up slightly as they cool.