Preheat the oven to 325°F (160°C). Line a half sheet pan with parchment paper or a silicone baking mat.
In a bowl, combine the sourdough starter and melted butter.
Pour the mixture onto the prepared baking sheet. Use a spatula to spread it thin and even. Sprinkle Everything Bagel seasoning across the top of the mixture.
Bake for 10 minutes, until it's set enough to score. Remove from the oven and use a knife or pizza cutter to score your desired cracker shapes.
Return the sheet tray to the oven and bake for an additional 25-35 minutes, or until the edges are golden brown, the bottom is golden brown, and the crackers are fully cooked through.
Notes
Avoid Burning: Watch the crackers toward the end of the bake time – once they're fully cooked through, they tend to burn quickly.
Storage Tips: Store in an airtight container (a tin or glass mason jar work best) to keep crackers crisp. If they soften over time, briefly reheat them in the oven at 300°F/150°C to restore their crunch.
Scaling the Recipe: Feel free to scale this recipe up or down, but ensure you don't put more than 300g of discard on a half sheet tray, or your crackers will be too thick. 200g on a half-sheet tray really is the sweet spot!