Preparation

• 1
  Preheat the oven to 200 degrees, or 180 degrees fan oven.
• 2
  Halve the plums, removing the stones, and place them in a saucepan.
• 3
  Add 2 tablespoons of cold water, the vanilla extract, the ground cinnamon and 2 level tablespoons of demerara sugar. Bring to a simmer, stir, cover the pan and cook gently for about 5 minutes.
• 4
  Stir the raspberries and blueberries into the plums. Mix the cornflour with a little cold water and stir it into the fruit. Cook gently for just a minute and then tip into a deep oven dish.
• 5
  In a large bowl, mix together the oats, flour and flaked almonds. Roughly chop the hazelnuts and stir them in too.
• 6
  Add the softened butter, cut into small pieces, then rub into the dry ingredients.
• 7
  Sprinkle in the sugar and stir well.
• 8
  Spoon in the warmed golden syrup and combine with the crumble topping; I found it helpful to use a knife to begin with, before stirring well with a metal spoon. The finished topping will still have some small clumps in it.
• 9
  Spoon the crumble evenly on top of the fruit and then bake in the preheated oven for 25-30 minutes, until the fruit is beginning to bubble up at the edges and the topping is golden brown.