Eight to 10
For the pastry
- 100g cold butter, diced
- 65g caster sugar
- 1 medium egg
- 185g soft pastry flour, plus extra for dusting
- A pinch of salt
For the filling
- 1 x 400ml tin of evaporated milk, which must be fridge cold
- 300g dark muscovado sugar
- Sour cream, to serve (optional)
- In a food processor, cream together the butter and caster sugar, then add the egg and pulse until mixed fully. Add the flour and salt to the processor and pulse until the dough comes away from the sides.
- Turn out on to a lightly floured surface and knead by hand to finish, just as long as it takes for the dough to come together and look shiny. Form into a disc and wrap in cling film.
- Leave in the fridge for at least an hour.
- Preheat the oven to 190C/170C fan/Gas 5.
- Roll out the chilled pastry on a lightly floured surface to about the thickness of a pound coin, and use it to line a 23cm tart case. Push the pastry right into the corners of the tin and prick the base with a fork. Leave the pastry case in the fridge for 30 minutes to allow the glutens to rest.
- Now blind bake the tart case. I line it with a couple of layers of heatproof cling film and fill with some old rice (push it into the corners). You could also use greaseproof paper and baking beans. Bake for 15 minutes then remove the cling film or paper and rice, and turn the oven down to 180C/160C fan/Gas 4. Put the case back in and cook until it is cooked evenly to a golden-brown colour all over – this could take another 15 to 20 minutes, but keep an eye on it so that it colours evenly.
- Meanwhile, for the filling, pour the chilled evaporated milk into the bowl of an electric stand mixer and add the muscovado sugar. Set the machine to whisk at high speed and leave it whisking for a full 10 minutes. It will expand to several times its original volume and the mixture, with a texture like thick double cream, should leave a trail when you hold a spoonful above the bowl.
- With the golden pastry case now out of the oven, turn the oven down to 120C/100C fan/lowest gas mark – leave the door of the oven open if necessary, to get the heat down.
- Pour the filling mixture into the tart case and bake for 15 minutes. Use a digital thermometer, if you have one, to accurately measure the temperature and keep the oven at 120C/100C fan/lowest gas mark.
- The filling will set to a shiny finish and if you touch it gently with a fingertip it should be slightly tacky. If you tap the side of the tin you will see a slight wobble, but it should otherwise be set.
- Take the tart from the oven and allow to cool briefly then place in the fridge for at least an hour before serving – you can also leave it overnight.
- Carefully cut it into slices using a warm, wet, sharp knife, and serve with a spoonful of sour cream, if you like.