Set your oven to 375°F (190°C). Line a baking sheet with parchment paper or a silicone mat.

In a large mixing bowl, combine the rolled oats, flour, baking soda, salt, and brown sugar. Stir well to distribute everything evenly.

Add the cold, cubed butter and use a pastry cutter or your fingertips to work it into the dry mixture until it resembles coarse crumbs.

Drizzle in cold water, one tablespoon at a time, mixing gently until the dough just comes together. It should hold when pressed, but not feel sticky.

Transfer the dough to a floured surface. Roll it out to about ¼ inch thick. Cut into circles, squares, or traditional rectangles using a cookie cutter or knife.

Place the oatcakes on the prepared baking sheet, spacing them slightly apart. Bake for 12 to 15 minutes, or until the edges are lightly golden.

Remove from oven and let cool on a wire rack. Serve with butter, jam, cheese, or plain—these oatcakes are versatile and satisfying.