Mix the batter. In a mixing bowl, combine the sourdough discard (200 g), cooled melted butter (28 g / 2 Tbsp), and shredded cheese (60 g). Stir with a spatula until everything is evenly combined.

Spread onto parchment. Line a baking sheet with parchment paper. Using your spatula, spread the mixture out evenly, aiming for roughly the thickness of a Cheez-It cracker. Don't spread it too thin, or the squares won't hold together and look like crackers once baked.

First bake. Preheat your oven to 350°F. Bake the spread mixture for 10 minutes.

Score into squares. Remove the baking sheet from the oven. Using a pizza cutter or a sharp knife, cut lines across the sheet in one direction, then across the other way, to create small squares. If you'd like, poke a hole in the center of each square with a toothpick - this helps keep them from puffing up too much in the second bake.

Second bake. Return the sheet to the oven and bake for about 30 more minutes. Keep an eye on them toward the end - exact timing depends on your oven, and you're looking for good color without overbaking.

Cool and break apart. Take the sheet out and let it cool and dry out a bit. Some squares will break apart on their own right along the scored lines, others you'll need to snap apart once everything has cooled.