01 - Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.
02 - In a mixing bowl, combine the sourdough discard, shredded cheddar, softened butter, sea salt, garlic powder, and smoked paprika. Mix thoroughly until all ingredients are evenly incorporated.
03 - Gradually add the all-purpose flour, mixing until a shaggy dough forms. Add cold water one tablespoon at a time, just until the dough comes together in a cohesive ball.
04 - Turn the dough out onto a lightly floured surface and knead gently until smooth and uniform in texture.
05 - Roll the dough out to approximately 1/8-inch (3 mm) thickness. Using a sharp knife or pizza cutter, cut into 1-inch (2.5 cm) squares.
06 - Transfer the cut squares to the prepared baking sheet. Prick each cracker once or twice with a fork and sprinkle lightly with coarse sea salt.
07 - Bake for 16–20 minutes, rotating the baking sheet halfway through, until the crackers are golden brown and crisp throughout.
08 - Transfer the crackers to a wire rack to cool completely. Once cool, store in an airtight container at room temperature for up to 1 week.