350g (3sticks) unsalted butter
175g (almost 1 cup) soft brown sugar
175g (almost 1 cup) muscovado sugar
450g (5 cups) rolled oats
3 tbsp golden syrup
6 tbsp cocoa
1) Pre-heat oven to 140C / gas mark 2 / 275F Grease a 7 x 11" baking tray or roasting tin
2) Melt the butter, syrup and sugars in a saucepan over a gentle heat.
3) Mix in the oats and cocoa
4) Tip the mixture into the greasted baking tray and bake for 20 minutes. They will still look moist after 20 minutes - this is fine and good.
5) Remove from the oven and leave to cool in the pan for about 20 minutes before slicing up. If you slice them too early, they will crumble and not hold their shape.
How to tell if flapjack is baked
I have found that there is a little bit of learning to be done when it comes to telling if flapjacks are ready or not. On a few occasions, I have made the mistake of thinking they look far too moist, even once they have had the suggested baking time, and cooked them for longer. This will leave you with crunchy, hard flapjack instead of a lovely chewy texture.
If you notice the mixture starting to bubble, remove it immediately from the oven. Ideally, you want to avoid bubbling, as this is an indicator that the flapjack is losing its moisture and heading towards crunchiness. If you like your flapjack crunchy, then keep baking it a little longer!
If you check your flapjacks after 20 minutes and they look like they would slide around the pan if you tipped it, they probably need another 5 minutes or so. A little bit of movement (think very gentle flapjack landslide) is fine.