Warm your tins of treacle and syrup in a pan of hot water to make it easier to pour.
While it’s warming, sieve your flour, ginger, nutmeg and a pinch of salt (if your butter’s unsalted) into a mixing bowl. Stir in the oats and chili flakes.
The easiest way to weigh your syrup and treacle is to do it in the pan you’ll be using, if you can. Do that, then add the sugar and butter and bring it all to a low simmer on a gentle heat, stirring it all together.
While that’s happening, grease a loaf tin or 20cm square cake tin.
Once your syrup, sugar and butter have combined, stir them into the dry ingredients. Mix in the beaten egg. You should have a very soft, almost liquid mix.
Pour the whole lot into your tin and baking tin, then place it in the oven for 1.25 – 1.5 hours, until firm in the centre. (Don’t worry if it sags a little in the middle, that’s normal. Even Delia says so.)
Remove from the oven and leave to cool for half an hour in the tin before turning out.