Preheat oven to 180C.
Peel and core the apple. Chop into chunks and place in a small saucepan, with a lid, and add a squeeze of lemon juice. Put the lid on, turn the heat to low and cook for about 10 minutes, until softened, stirring now and then to prevent it sticking. If it seems a little too dry after the first 5 minutes add a tsp of water.
Place the nuts in a small plastic bag and bash with a rolling pin. Spread out the broken up nuts and the oats on an ungreased baking sheet and place in the oven for 10 minutes, until lightly toasted.
Put the raisins and cranberries in a small saucepan, cover with the water and bring to a simmer. Simmer over a low heat for 10 minutes, to plump up the fruit. This prevents it from burning when the biscuits are cooking. After 10 minutes, drain through a sieve and put aside to cool a little.
Put the honey, fruit sugar, stewed apples, oil, vanilla extract and egg in a large mixing bowl and beat with an electric mixer for 5 minutes until it is pale and mousse-like in texture and has almost doubled in volume. Sift the flour, baking powder, bicarbonate of soda and cinnamon into the mixture and mix together with a spoon. Add the fruit, nuts and oats and mix well.
Line two large baking trays with baking parchment. Using two teaspoons, dipped in hot water, spoon dollops of the mixture onto the parchment, about 2 cm apart (they don’t spread very much but you want to allow a bit of space). If you don’t mind getting your hands messy or are making these with children, you can roll balls in your hands instead of using the spoons. Flatten slightly. You should be able to get about 10 on each tray. Bake in the preheated oven for 10 minutes. Leave on the trays for a couple of minutes, then transfer to a wire rack to cool completely.