Queen of baking Mary Berry, makes a crunchy apple crumble with walnuts and sunflower seeds for a Weekday supper on Mary Berry Cooks.

To get the exceptional crunch to her crumble, Mary cooks the apples and the nutty topping separately.

The ingredients for Mary’s delicious dessert are: 1.5kg cooking apples, ½ lemon, juice only, 100g light muscovado sugar, 50g plain flour, 50g porridge oats, 150g light muscovado sugar, 150g walnuts, roughly chopped, 50g sunflower seeds, 100g softened butter.

To make prepare the dessert: Peel and core the apples, then cut them into thin slices. Place in a small flameproof casserole with the lemon juice, sugar and six tablespoonfuls of water.

Bring to the boil, then place in a preheated oven at 180C and cook for about 20 minutes, or until the apple is tender but has not fallen to a pulp.

Put the dry topping ingredients in a mixing bowl and rub in the butter until it is evenly distributed and the mixture has formed small clumps.

Spread the mixture evenly over a baking tray and bake for about 20 minutes, or until golden-brown and crisp.