These are fantastic for quick and easy pudding. We are making quite a few with apples so we can easily have apple things when they are no longer on the trees. We have a number of apple trees, none of them are great and the sheep have killed a few by eating the bark. We plan on planting more next year.
The idea is to make the crumble in a freezer proof and oven proof container with some kind of top to keep them safe. I use the smallest one of these
parfait jars (and sometimes the next size up) as all the supermarkets and various other shops here sell them. You want something with a wide mouth.
The topping is oat crumble see
here. I am going to try some with normal crumble as well. The oat works well though as it is quite flaky and dry and doesn't go soggy or hard with freezing and then reheating.
You could use any fruit filling but for these I used apples.
Peel and core then chop finely 600g of apples
Stew them in a pan with some lemon and water until they are mushy but not pureed (unless you want them like that) then add some sugar to taste and stir until disolved.
Meanwhile make the oat crumble using 200g of oats (100g butter and sugar)
Fill the jars about 1/2 full then fill up with the crumble. Don't pack the crumble down and it should not go above the level of the top of the jar.
Put the lids on and leave to cool and then put in the freezer.
Take them out some hours before you need them to let them thaw and cook for about 15 or 20 mins (or longer if bigger) at 180C, or sometimes I put them straight in to a very cool oven (100C) until they are thawed then cook them for about 15 mins at 180C.