In a large pan, on a low heat, melt butter, sugar and syrup till runny. Mix in the oats really well, making sure none are left uncoated by the butter-sugar mix.
Pour into a 20x30cm tray lined with baking parchment. Level out the mix with a spatula. Bake in a preheated oven at 160 C / Gas 3 for 25-35 minutes. (These should look seriously under-baked, that's the point. When they are done, if you grip the pan and give it a little wobble, it will look uncooked. This is perfect.)
Cover with a clean tea towel and leave for a whole day or overnight till completely cold. If you try and turn them out before, they will be ruined. When they are completely cold, turn them out and cut into squares. Wrapped in cling film or foil these will last a week at least. They freeze well too!
Brilliant recipe and really easy to make! I only made a quarter of the recipe and so only cooked it for about 20 minutes.. what i love most about this recipe is that you don't have to stick to the recipe to rigidly and it always turns out fab! With the last batch I squashed some fudge pieces into it after cooking.. amazing! - 09 Nov 2011