Betty Neels never mentions oliebollen as having raisins in them, but most of the recipes I found had raisins. Lots of raisins. I personally loathe cooked raisins - so I hunted around until I found a recipe without them. Very easy to make...but the recipe makes enough to feed a crowd. Next time I will have to cut the recipe in half - or invite a lot of people over to eat them.
Basically they are fried balls of moist/sticky bread dough. I was careful to cook them completely - I don't like doughy bread - and they do turn out the consistency of bread. I think if you left the powdered sugar off they wouldn't be too bad for a sandwich. I threw some chopped apple pieces in some of the dough - the apples added a nice fruity touch without being like raisins.