If you're using rolled oats, put these in a blender and whizz until you get fine oatmeal.
Add the remaining ingredients, blend for 1-2 minutes, until you get a dense, coarse mixture.
Put the mixture into clingfilm and roll it up into a sausage shape. Rest in the fridge for 2-3 hours (or 30 minutes in the freezer if you're in a hurry).
When the dough is hard, cut into 1 inch segments. Form balls from these between your (clean!) palms to roll and coat them with desiccated coconut or cocoa powder.
Store in an airtight box or jar in the fridge until use.