This is my recipe for Flapjack, inherited from my English mother. It doesn't have golden syrup in it, but you could try using 3 oz of Lyles with 3 oz brown sugar and seeing how it turns out. I'm sure it would work quite well.
These biscuits (cookies in America) are called Anzacs because they were baked by Australian women and sent to their ANZAC soldier sons/husbands serving in Europe and Middle east during WW I. It was more like 2 months before they were received back then, so they certainly do travel well! :-) ** Please note that 1 Australian Tablespoon = 20 mls whereas in most others countries it = 15 mls. Anzac Biscuits