Pulse the dry team. In a food processor, blitz the oats until coarsely ground (15–20 seconds). Add whole-wheat flour, salt, paprika, and garlic powder. Pulse to combine.
Cheese it up. Add grated cheddar and pulse a few times to distribute evenly. You're building flavor insurance here.
Cut in the butter. Drop in cold butter cubes and pulse until the mixture looks like coarse crumbs with pea-sized bits. No processor? Use a pastry cutter or your fingertips. Work quickly to keep the butter cold.
Add water to bind. Drizzle in 2 tbsp ice water and pulse. If it looks dry, add more water 1 tbsp at a time until the dough starts to clump. You're aiming for a cohesive, slightly firm dough—not sticky.
Chill the dough. Turn the dough out, press into a disc, wrap, and refrigerate for 20–30 minutes. This relaxes the flour and keeps the crackers from shrinking.
Preheat and prep. Heat oven to 350°F (175°C). Line two baking sheets with parchment.
Roll it thin. On a lightly floured surface (or between two sheets of parchment), roll the dough to about 1/16–1/8 inch. Thinner = crispier.
Cut your shapes. Use a small cutter or a knife to cut 1-inch squares. Poke a small hole in the center with a skewer for the classic look and better crisp.
Finish and bake. Transfer to baking sheets. Lightly brush with egg wash if using and sprinkle with a whisper of salt. Bake 12–16 minutes, rotating the pan halfway, until edges are deep golden and centers feel set.
Cool for crunch. Let crackers cool completely on the sheet. They crisp as they cool. Try to resist “testing” every other cracker. Or don't. Your call.