Luckily for me, the official GBBO website has the full website with complete instructions on so I don't have to guess at timings, quantities or method! Which is great because this is a strangely complicated recipe that requires hours to do. I'm not exaggerating - from weighing my first ingredients out to having a finished product cooked it took over 4 hours. You can make these using store bought puff pastry which would speed the process up but where's the fun in that?
However - they are completely worth the effort.
They're not quite what I'd call a biscuit, more of a pastry to me, but they are absolutely yummy and I would definitely make them again. I'd probably make them from scratch again; it is a lovely feeling to know that you've put all the effort in. I did run into a couple of butter related issues but overall they seem to have turned out ok! I doubled the recipe so I ended up with 16 decent sized biscuits.
I learnt a few of things along the way -
1) Don't rush the chill times. Equally, don't overchill. My pastry was fine but my butter layer cracked when I tried to incorporate it. I'm not sure if this is because I overchilled it (I chilled it for nearly an hour rather than half an hour as it still felt squidgy) or because I underchilled it but it meant that I had to attempt to incorporate squidgy butter into hard pastry... In the end I dolloped as much underneath and on top as I could and rewrapped it in clingfilm. This made it easier to get the butter into the pastry. Arguably this has affected the end result, as puff pastry puffs from the butter in between the pastry layers.
2) Turn them in the middle of the cooking time. I often neglect to do this with other biscuits but it really makes a difference with these; if you don't turn them then the bottom sugar/cinnamon combination will probably catch and burn. Turning them ensures a nice colour all around.
3) Don't skimp on the sugar and cinnamon mixture. It looks like a lot to go in but if you skimp then you'll end up with quite bland puff pastry that doesn't really resemble a biscuit in any way.
4) Roll the pastry as tight as you can at the penultimate stage. A loose roll will mean that it's harder to cut your biscuits and they will not make a 'whole' biscuit when they're baked.
5) Using a small rolling pin is easier than a large one when you're rolling out the rounds prior to baking. Aim for as thin as you can get - the thinner they are, the better the taste.
Yes, it's a four hour effort. But you're actually only working on these every 30 - 45 minutes and only for five to ten minutes at the time. Set aside a morning and get them done!