I've made the LMP out of the EDC 4 times with no problems whatsoever, always turns out perfectly. Today though I wanted to make a big one, so made double quantity - pastry was perfect, but when it came to the lemon filling I could not get it to thicken. I'm sure I doubled all quantities correctly, and I extended the cooking time, first by 6 minutes on top of the usual 10, then added more cornflour and cooked an extra 6 minutes but still no thickening. I put it in to the fridge anyway hoping it would thicken as it cooled, but it's been in there nearly 3 hours and while it is a bit thicker it is still way too runny to use.
It's too late to make another one as I need it for tonight, so Cheesecake shop here I come
, but was hoping someone might be able to suggest what went wrong so I know for next time?