Blackberry and apple cinnamon crumble cake

8
1 hour 30 minutes

Ingredients

Crumble cake

  • 120g of walnuts
  • 1 tbsp of flax seeds, milled
  • 3 tbsp of water, filtered
  • 100g of ground almonds
  • 70g of chestnut flour
  • 1 tsp ground cinnamon
  • 1 tsp baking powder, gluten free
  • 1 tsp bicarbonate of soda
  • 1/2 tsp pink Himalayan salt
  • 1/2 lemon, zest only
  • 80g of maple syrup
  • 1 tsp vanilla extract
  • 50ml of extra virgin rapeseed oil, preferably cold pressed
  • 2 apples, such as Cox or Granny Smith, weighing 250g in total
  • 250g of blackberries, fresh or frozen

Apple purée

  • 6 apples, such as Cox's, each weighing 120–140g

To serve

  • ground cinnamon, or mesquite
  • 250g of natural yoghurt

Method

1
Preheat the oven to 180°C/gas mark 4
2
Begin by preparing the apple purée. Wash and dry the apples, then cut into quarters. Place on a baking tray and bake for 20–30 minutes, until soft
3
Remove from the oven and leave to cool, reserving any liquid in the tray, then transfer the apples and their juices to a blender and blitz to form a smooth, sweet purée
4
Preheat the oven to 170°C/gas mark 3.5. Line the bottom of an 18–20cm loose-bottomed cake tin with baking and grease the sides with a little oil
5
Place the walnuts on a baking tray and toast in the oven for 5–8 minutes until beginning to colour. Leave to cool, then weigh out 80g and finely chop. Set the remaining walnuts aside
6
Combine the milled flax seeds with the water and leave for 15 minutes to form a gel, stirring occasionally
7
In a large bowl, mix together the finely chopped walnuts, ground almonds, chestnut flour, cinnamon, baking powder, bicarbonate of soda, salt and lemon zest. Make a well in the centre and add the flax gel, maple syrup, vanilla extract, oil and 60g of the apple purée. Mix well until combined
8
Divide the mixture equally in two, placing half in the cake tin. Spread it out evenly with a palette knife to form a 1cm layer. Peel, core and thinly slice the apples and spread them over the cake mix, overlapping them in a circle
9
Scatter the blackberries over the apple slices and top the fruit with the rest of the cake mix. The mix will be sticky so use your fingers to dab small bits of the mix over the blackberries (it doesn't matter if some berries are still showing, but try to cover most of them)
10
Sprinkle the remaining walnuts over the top of the cake, breaking them roughly between your fingers as you do so. Press them into the cake mix slightly. Bake for around 30 minutes, rotating the tin halfway through baking
11
If the top is looking a bit dark, turn down the oven to 160°C/gas mark 2.5 for the last 10–15 minutes. It is ready when the top is firm to touch and a rich golden brown, the nuts will be well toasted and a skewer inserted into the centre of the cake comes out almost clean
12
Serve warm with an extra dusting of cinnamon or mesquite if you like and natural yoghurt. This is best eaten fresh but will keep for up to five days in a sealed container in the fridge