Blitz the dates in a food processor until they have formed a rough paste.
Add the pistachios, oats, water and around half of the shredded coconut.
Blend again until thoroughly mixed.
Tip the mix out of the blender on to your work surface and roll it into a rectangle about 2 cm thick.
Cut the rectangle into 10 equal bars.
Put the remaining desiccated coconut into a tub or plate, then roll the bars around in it one at a time until they are evenly coated with coconut.