Preheat the oven to 180°C/160°C/gas mark 4. Line a shallow baking tray with greaseproof paper. Place the almonds in a food processor and blend until ground. Remove the stones and any hard ends from the dates. Add the dates, honey and cacao powder to the food processor and blend.
Peel the apples, remove the cores, chop into chunks and place in a pan. Pour 500ml boiling water over the top and place on the hob over a medium heat for 10 minutes. Drain the water and add the apple to the food processor.
Blend the mixture for 30-60 seconds until combined, then scoop on to the baking tray. Place in the oven and cook for 30 minutes, until the top goes firm. Allow the brownies to cool at room temperature for 20 minutes, then place in the fridge for 10 minutes before cutting into 10 pieces.