Method
- Line a 20cm square tin with baking parchment.
- Put the apple, blackberries, maple or date syrup, lemon juice, zest, vanilla extract and 20ml water in a medium saucepan. Bring to the boil, then reduce to medium heat and simmer for 10 minutes, mashing the apple with a fork every so often until soft and most of the liquid has evaporated. Remove and set aside to cool.
- For the base, place all the ingredients into a food processor and pulse until well combined. Press the mixture in an even layer onto the base of the tin. Using a fork, prick all over and then leave in the fridge for 15 minutes to firm up.
- For the topping, place the margarine, flour, sugar and cinnamon into a food processor and pulse until well combined. Remove and transfer to a small bowl. Add the pecan nuts and oats and stir.
- Preheat the oven to 180°C / Gas mark 5.
- Bake the base for 15 minutes. Remove and leave to cool for 5 minutes.
- Spread the filling on the cooked base carefully spreading it evenly, right to the edges.
- Add the topping and bake for a final 30 minutes.
Leave to cool completely in the tin – about 30 minutes before cutting into 12 bars.