Easy and delicious! This pastry traybake is packed with apples and is much easier to make than a pie. Simply roll the pastry out into two even rectangles and you're more or less done - no trimming or blind baking required!
Preheat oven to 180 C / Gas 4. Lightly grease a 22cm x 32cm traybake tin.
In a medium bowl, stir together the flour and salt. Rub in the butter until mixture looks like breadcrumbs. With a fork, stir in 150ml milk and egg yolk to form a pastry. Divide pastry into 2 equal parts. On a lightly floured surface, roll out 1 piece of pastry to fit the base of the traybake tin; press pastry down lightly to form a smooth base in the tin.
Sprinkle crushed cornflakes over the bottom layer of pastry, then layer the apples on top. Stir 200g of caster sugar and 1 1/2 teaspoons of cinnamon and nutmeg together in a small bowl; sprinkle over the layer of apples. Roll out the other half of the pastry and arrange on top to cover the apples.
Brush the top of pastry with beaten egg white and sprinkle 2 tablespoons sugar and 1/2 teaspoon of cinnamon on top.
Bake for 45 minutes to 1 hour in the preheated oven. The top should be golden brown.
To make the icing for drizzling on top: Mix together the icing sugar, 1 and 1/2 tablespoons of milk and 1/2 teaspoon of vanilla until smooth; drizzle over traybake or sliced bars while they are still warm.