Soak the cherries. Place the sour cherries in a small bowl, warm the orange juice slightly and pour over the cherries. Leave to soak for at least 20 minutes while you prepare the brownie mixture.
Preheat the oven to 180°C / 160° Fan / Gas 4. Line the base and sides of a 24cm square baking tin with baking parchment.
Prepare the apple purée. Place the apple pieces in a small pan with 2 tbsp water and the teaspoon of sugar. Bring to a simmer, cover and ook over a medium heat for 5-7 minutes until very soft. Transfer to a small bowl, mash until smooth and leave to cool.
Make the browniesIn a bowl, sift together the plain flour, cocoa powder and bicarbonate of soda. Stir in the wholemeal flour and brown sugar until evenly combined. In a jug, whisk the egg, with the mashed apple, buttermilk and vanilla extract until smooth. Add to the dry ingredients and mix until just combined.
Fold through the soaked cherries along with any remaining orange juice. Spoon the mixture into the prepared tin and spread evenly.
Warm the peanut butter slightly in the microwave for a few seconds to loosen, then drizzle over the brownie batter and gently swirl through using the tip of a knife.
Bake for 28-30 minutes until just set on top but still slightly soft in the centre. Leave to cool completely in the tin.Once cooled cutting into 12 squares.
