Combine the ripe banana, raisins and warm water in a bowl. Let it stand for 10 to 15 minutes until the fruit is soft and moisture soaks well into the dry fruit.
Meanwhile, roast the almonds at 160C for 10 minutes and let it cool. Chop the almonds.
Place the fruit, almond powder, mixed spice into a food processor and blend until paste-like, adding the chopped almonds last. Blend until the mixture starts to stick together and clum against the side of the processor.
Transfer the mixture on a large piece of parchment or wax paper and spread the mixture with a spatula to a 10cm width rectangle, 1.5cm thickness. Refrigerate for about 60 minutes before cutting it into bars.
Wrap the individual bars into plastic paper and keep refrigerated for up to 3 weeks.