Heat the oven to 180C/160C fan/gas 4. Oil and line a 20cm square tin. Pit the dates and tip into a bowl. Pour 150ml boiling water over them and let them soak for about 20 mins. Heat a dry frying pan over a medium heat and tip the walnuts in. Toast for 3-5 mins until fragrant and lightly browned. Set aside to cool.

Drain the dates, reserving 1 tbsp of the liquid. Tip the oats into a food processor and blitz until finely chopped. Add the coconut oil, black beans, banana, cocoa powder, maple syrup, vanilla, bicarbonate of soda, baking powder, salt, and the drained dates. Pour in 1 tbsp of the date liquid. Blitz until smooth then stir in the walnuts and chocolate chips. Spoon into the tin and smooth out. Bake for 30-35 mins until set and leave to cool completely in the tin. Once cooled, leave overnight in the fridge to set (this makes them extra fudgy and easier to slice). Sift over some icing sugar to serve. Will keep chilled in an airtight container for up to three days.