Preheat the oven to 160C (fan) and grease the cake tin.
In the large mixing bowl, beat the butter until creamed & pale.
Add the sugar and beat again until thoroughly combined.
Very gently mix the flour in using a fork until you end up with fine breadcrumbs.
Tip the breadcrumbs into the cake tin and press down firmly. Cut 8 wedges using a sharp knife
Now bake at 160C for around 50minutes. This gives you a harder, dunkable shortbread. For a softer one, bake for about 45minutes. I re-cut the wedges when the shortbread comes out of the oven just to make sure the wedges come apart cleaning.
Sprinkle with a little bit of sugar & leave to cool before removing from the tin.