Combine all ingredients in a food processor and process until a thick, grainy dough has formed.
A good way to check if the mixture has the right consistency is to try and roll a small amount into a ball. You want to be able to roll it into a ball easily without it sticking all over your hands. If the mixture is too sticky, add a bit more oats and process again. If the mixture is clumpy and not holding together well, add some more raisins and process again.
Once your mixture is ready, roll some of it out on a flat surface using your hands so a long tube (about 1cm thick) is formed. Use a knife to cut this tube into little pieces, about 1cm long. Place the little pieces on a large plate or tray, in a single layer. Repeat until all the mixture is used up.
Place the plate/tray in the fridge and chill for about an hour.
These will keep in the fridge for up to two weeks.
Makes at least a hundred itty bitty bites, but this will depend on how big you make them.