Custard Apple and Apple Pie

Ingredients

• 220 g plain flour
• 2 tbsp caster sugar
• 110 g unsalted butter, chilled, chopped
• 1 egg yolk
• pouring cream, to serve
• 4 large (about 800 g) Granny Smith apples, peeled, cored, sliced
• 1 (about 550 g) custard apple, seeds removed, flesh scooped
• 110 g (½ cup) caster sugar
• 2 tbsp plain flour
• 1½ tsp ground cinnamon
• 105 g (¾ cup) plain flour
• 75 g (⅓ cup) caster sugar
• 65 g (¼ cup firmly packed) brown sugar
• 100 g unsalted butter, chilled, chopped