BBC Food - Recipes - Peach and blueberry streusel cake

Ingredients

• 125g/4oz self-raising flour
• 75g/3oz unsalted butter
• 75g/3oz soft light brown sugar
• ½ tsp ground cinnamon
• 1 tbsp demerara sugar
• 250g/8oz butter , plus extra for greasing
• 250g/8oz plain flour
• 125g/4oz granulated sugar
• 150g/5oz light soft brown sugar
• 2 tsp baking powder
• ½ tsp salt
• 3 free-range eggs , separated
• 250ml/8floz whole milk
• 200g/7oz fresh blueberries
• 1 x 400g/7oz tin peach slices in syrup, drained
• 200g/7oz blueberries
• 65g/2½oz caster sugar
• 1½ tbsp plain flour
• 1½ tsp lemon juice