01 - In a food processor, pulse the flour, fine sea salt, garlic powder, and smoked paprika several times until evenly combined.
02 - Add the cold diced butter and pulse until the mixture resembles coarse crumbs with no large butter pieces remaining.
03 - Add the grated sharp cheddar cheese and pulse until it is evenly distributed throughout the mixture.
04 - Add the sourdough discard and pulse until a cohesive dough ball forms. Avoid overmixing to keep the crackers tender.
05 - Turn the dough onto a lightly floured surface, shape it into a flat disc, wrap tightly in plastic wrap, and refrigerate for at least 30 minutes to firm up.
06 - Preheat the oven to 350°F (180°C). Line two baking sheets with parchment paper and set aside.
07 - Roll the chilled dough out to approximately 1/8 inch (3 mm) thick. Use a knife or pizza cutter to cut into 1-inch (2.5 cm) squares. Transfer the squares onto the prepared baking sheets, spacing them about 1/2 inch apart.
08 - Prick each cracker square once or twice with a fork, then sprinkle lightly with flaky sea salt.
09 - Bake for 20–25 minutes, rotating the baking sheets halfway through, until the crackers are golden brown and crisp to the touch.
10 - Let the crackers cool completely on the baking sheets. They will continue to crisp as they cool. Store in an airtight container at room temperature.