Vegan Dutch Apple Pie (Apple Crumble Pie)

For the pastry (sub store-bought shortcrust pastry if desired):

• 215 g plain flour (~1 + ¾ cups)
• 135 g Vegan margarine*, cold (½ cup + 1 tablespoon)
• 15 g icing sugar (1 tablespoon)
• 1 Tablespoon ice cold water

For the filling:

• 4 medium green apples (I used Granny Smith)
• Juice of ½ a lemon
• 330 ml water (1 + ⅓ cup)
• 2 Tablespoons cornflour/cornstarch
• 100 g caster sugar (½ cup)
• 1 Teaspoon lemon zest
• 1 Teaspoon cinnamon (the ground, dried powder)

For the crumb topping:

• 300 g plain flour (~2 + ⅓ cups)
• 175 g soft light brown sugar (¾ cup + 2 tablespoons)
• 1 Teaspoon cinnamon
• 200 g Vegan margarine, cold (~¾ cup + 1 tablespoon)