Preheat the oven to 170°C. In a food processor combine the chickpeas, peanut butter, maple syrup, vanilla, egg and water and blend. Add the oats, baking soda and salt. Process for 1-2 minutes until you have a smooth batter. Fold in the chocolate chunks. Transfer to a square baking dish (20x20cm) lined with parchment paper and bake in the oven for 20 minutes. Let it cool completely, remove from the baking dish and cut in pieces.