Heat oven to 180C/160C fan/gas 4
and line a 20 x 30cm cake tin with baking
parchment. Put the apple in a small pan
with 2 tbsp water. Cook for a few mins
or until the apple starts to soften.
Meanwhile, make the crumble topping.
Rub the butter into the flour, sugar and
lemon zest until it resembles big
breadcrumbs, then set aside.
Beat the butter and sugar in a large
bowl until fluffy, then gradually add
the egg. Tip in the flour and milk, and
continue to beat until everything is
combined. Incorporate the apples then spoon the mixture into the
tin, smooth the surface, then dot with
the raspberries. Sprinkle over the
crumble topping and bake for 45 mins
or until a skewer inserted comes out
clean, and the topping is golden.