Core and slice the apple, and place in a small frying pan with the dairy-free margarine, caster sugar and apple juice. Bring to the boil and cook for 3 minutes, then add 100g of the blackberries. Continue to cook until the liquid had reduced to a syrupy sauce, then remove from the heat and set aside.
To make the pancake batter, blitz the apple sauce, dairy-free milk, flour and salt in a blender or food processor, or with a hand-blender, then mash in the remaining 50g of blackberries with a fork.
Heat a large frying pan, add a knob of dairy-free margarine, and pour in 2 tbsp batter to make a small, fairly thick pancake. Repeat to make 2 or 3 in the pan at a time if there is space. Cook for a minute or two until golden brown underneath, then flip over and cook for a further minute. Remove from the pan and serve topped with the fruit and drizzled in the syrup.