Mix together the flour, oats, cornmeal and sugar. Rub together with fingertips to remove any lumps in the sugar.
Mix in the dried cranberries.
Add the butter and rub it in.
Continue to mix till everything comes together into a ball. Do not be heavy handed, knead or overmix. Just bring everything together.
Shape into a log and flatten to about 12 inches long and about 3 inches wide.
Wrap in plastic wrap and chill for about 2 hours.
Pre heat the oven at 180 deg C and line a baking tray with foil or parchment.
Unwrap the dough and with a sharp knife, quickly cut the dough into 16-17 triangles.
Arrange the triangles on the lined baking tray, a little apart from each other.
Place the tray in the centre of the pre heated oven and bake for about 15-17 minutes or till lightly browned.
While still hot, trim the edges with a sharp knife and sprinkle a little granulated sugar over them ( if using ).
Cool on tray for 2 minutes and then transfer to a rack to cool completely.
Store in air tight containers.