To make the apple filling, peel and core the apples, then chop into small chunks. Add to a pan on a low heat along with the light brown sugar, cornflour, cinnamon and mixed spice. Stir everything together
Cover with a pan lid, and cook the apple for 10-15 minutes until soft
Remove from the heat and leave to cool completely
To make the crumble, pre-heat your oven to 180C Fan/200C/375F/Gas Mark 5, and line a baking tray with baking paper
Put the plain flour, light brown soft sugar and cinnamon into a bowl and stir together
Add the butter and use your fingers to rub the butter into the dry ingredients until it resembles breadcrumbs. You can also use a fork to do this
Spread it out onto a lined baking tray and bake for 10-15 minutes until it is golden and feels firmer to the touch (it will firm up more as it cools)
For the cupcakes, pre-heat your oven to 160C Fan/180C/350F/Gas Mark 4, and line a cupcake tin with cupcake cases
To make the sponge, mix together the butter and sugar, ideally using an electric mixer, until smooth
Add the eggs and whisk well
Then gently whisk in the self raising flour, cinnamon and mixed spice
Divide the mixture between the 12 cupcake cases
Bake them for 20-25 minutes or until they are golden brown and a skewer inserted in the centre of the cupcakes comes out clean. Leave to cool completely
Use a cupcake corer or a knife to make a hole in the middle of each cupcake
Fill the holes with the apple filling
Make the buttercream by mixing the butter on it's own for a few minutes, then add the cinnamon, icing sugar and milk, and mix until smooth. For best results use an electric hand mixer or a stand mixer with the paddle attachment. If the buttercream is too stiff you can add a little more milk
Pipe the buttercream onto each cupcake using a piping bag fitted with your chosen nozzle (I used an Ateco 829 nozzle). Or spread on with a spoon
Add the rest of the apple filling to the top of each of the cupcakes
Sprinkle the crumble over the top - or wait and do this later if not serving immediately as it will go softer from being in contact with the buttercream after a little while
Store in an airtight container in a cool place, eat leftovers within 3 days