Preheat the oven to 350℉ and line a baking sheet with parchment paper.

Melt the butter in a large measuring cup or mixing bowl and let it cool until just lukewarm. Measure in the sourdough discard and salt, and stir together with a spatula until well combined. Add cheese and stir until well incorporated.

Pour the mixture onto your parchment-lined baking sheet and use an offset spatula to spread it into a thin, even layer that is almost transparent (for reference, my dough rectangle measured 11x14 inches).

Lightly sprinkle the top with flaky salt - don't overseason.

Bake for 10 minutes then remove from the oven and use a pizza cutter to score your crackers into bite-size squares. For the classic cheese cracker appearance, you can use the back of a wooden skewer to poke a hole in the center of each crack.

Return to the oven and bake another 20 minutes or until the crackers are golden and hardened. If crackers are not firmed up, it may be due to not spreading them thinly enough, just continue to bake until they are firm when you tap the tops.

Remove from the oven and let cool on the baking sheet to let them fully dry out. Once they have cooled completely, store in an airtight container or zip bag.