1. Start by making the crumble. Preheat the oven to 180 degrees. Add the flour and butter into a mixing bowl. Rub the butter through the flour with your fingertips until it is evenly spread, soft and crumbly. Add the brown sugar and mix evenly through.
  2. Transfer the crumble mix on to a large oven tray lined with parchment paper and spread it out in an even layer. Place in the oven and cook for 15 minutes at 180 degrees until golden brown, stirring every three to four minutes to prevent the outside of the crumble mix from burning and keep the mix evenly cooked. Then, remove the tray from the oven. Precooking the crumble mix like this will keep the crumble topping from going soggy when baked on top of the fruit mix.
  3. Peel the apples and remove the core, then chop into small cubes. Place a large saucepan on a medium heat and add the apples, lemon juice, sugar, butter, cinnamon and vanilla. Cook over a low to medium heat for eight to 10 minutes, stirring occasionally, until the apples are softening but holding their shape, then remove from the heat.
  4. Add the blackberries to the hot apple mix and stir them through, then transfer the fruit mix to a round oven dish. Add the crumble mix evenly on top, then place in the oven at 180 degrees to bake for 15 minutes.
  5. While the crumble is baking, make the spiced Chantilly cream. Add the cream, icing sugar and crème fraîche to a large bowl. Season with the vanilla, mixed spice and nutmeg, then whisk until stiff peaks form.
  6. Remove the crumble from the oven and allow to sit for five minutes before serving with the spiced Chantilly cream on the side.