In a food processor, combine sharp cheddar cheese, sourdough discard, unsalted butter, all-purpose flour, garlic powder, onion powder, and salt. Pulse until the mixture resembles wet sand and holds together when squeezed, about 30 seconds.

Gather the dough into a disc and wrap it tightly in plastic wrap. Refrigerate for at least 30 minutes.

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

Once chilled, roll out the dough on a lightly floured surface to about 1/16th inch thickness. Cut into desired shapes.

Sprinkle the shaped crackers with flaky salt for added flavor, then bake in the preheated oven for 18-22 minutes.

After baking, let the crackers cool completely on the baking sheet.