Instructions

1. Crush half the raspberries to a coarse powder and leave the other half whole, as the ingredient row asks. The crushed half does the flavouring and the colouring; the whole half comes back as fruit you can bite.
2. Whisk the cornflour through the powdered milk before anything else joins them. Starch introduced to a wet mixture clumps, and a lump of raw cornflour in a pudding never cooks out of it.
3. Fold in the sugar, the powdered egg and the shredded coconut, keeping the raspberries until last. Stirring the berries in early breaks the whole ones down into the powder and you lose the contrast you just built.
4. Shake the finished mix in a jar rather than stirring it in a bowl. Berry pieces are far lighter than milk powder and will float to the top of a bowl, so every scoop you take out is a different recipe.
5. To cook it, whisk the dry mix into cold milk or water off the heat, then bring it up slowly and stir until it coats the back of a spoon. Starch sets all at once near the boil, and a mix tipped into already-hot liquid seizes in strings around the whisk.
6. Vacuum sealed with an oxygen absorber it holds a month in the cupboard, six months in the fridge and a year in the freezer. The powdered milk sets that limit — milk fat picks up a stale, cardboard smell long before anything looks wrong.
7. In a zip bag instead, treat it as a month in the fridge and five days once it comes out. Look at the berries before you cook: any that have gone soft or tacky mean moisture found its way in, and the batch is finished.