This isn't my recipe but I think I'm going to start posting here for my own reference rather than any other reason. I usually use the BBC Good Food page for anything 'general' that I'm looking for and then customise it based on what we all want. My preference would have been to make festive flapjacks by adding mincemeat, but I was outvoted by the kids who wanted chocolate chips.
The most reliable one I've found is the BBC's Yummy golden syrup flapjacks but I often substitute honey for golden syrup, if we either don't have any, or if my daughter is helping, as she's obsessed with honey in her porridge, on her toast or straight out of the jar!
This December's Christmas flapjacks were one of the sweetest ever, I think, made with half honey, half golden syrup and a big handful of chocolate chips. The kids' verdict was 'WOW these are good' and they both had seconds. Dentist here we come.