Heat oven to 180°C / 160°C (fan oven) / 360°F / Gas Mark 4. Peel, core and slice the apples. Grease a large serving dish with 25g of the butter and tip in the apple. Scatter the raisins over the top.

In a separate dish beat the remaining butter and sugar together for 10 mins until the butter turns pale and the sugar starts to dissolve. Beat in the eggs, then carefully fold in the flour with a large spoon. Spread the batter over the apples, then bake for 45 mins until golden. Serve with the custard, below.