(I have also added a second photo to the original recipe).
I was contacted by Freyja (if you know Icelandic you can read her comments), who tried the recipe and wrote back to say that the cookies tasted a bit too much of raw oatmeal. She also suggests using icing sugar instead of regular sugar, which I agree with, since there isn't really enough moisture in the dough to dissolve the sugar grains.
The balls came out looking just like bakery made ones, but neither the taste nor the texture was enough like the coconut balls you can buy from bakeries. Bakery coconut balls are chewier and the texture is similar to thick cookie dough. These are harder, the sugar has not melted properly (as Freyja commented) and the oatmeal taste is too raw. Rum or sherry drops could help with the raw taste, as could reducing the oatmeal and replacing part of it with dessicated coconut and increasing the butter slightly. Melting the sugar in the milk or using icing sugar and processing the oatmeal into finer pieces in a blender might help with the texture, as could mixing it in a mixer instead of by hand. Finally, it could be made softer by using good quality Dutch process cocoa instead of melted chocolate. I think I will test these changes the next time I make them (whenever that will be).
After sampling a few, I stored the balls in the refrigerator and tried one the next day and another one the day after, and found that they improve with age. On day 2 the raw taste was gone, while the sugar still crackled slightly between the teeth, but on day 3 the sugar had dissolved and the texture was more like the bakery stuff. The problem is, they just look too tempting to store them for this long and I can not see it happening in homes with children.
Freyja came up with this recipe, which she says is delicious (it certainly sounds like it):
175 g dark chocolate
1/2 dl oatmeal
50 g butter
vanilla essence to taste
Mix marzipan, butter and vanilla, and oatmeal mixed in. Melted chocolate added to the mixture, rolled into balls and coated with coconut.
The next time I need to make something with marzipan, I think I will try this recipe. It sounds good enough for Christmas, but whether it resembles the bakery recipe remains to be seen. I imagine the texture must at least be similar.
P.S. I seem to recall that, as a child taking my first year of home cooking classes, I made coconut balls from mashed potatoes into which were kneaded icing sugar, cocoa powder and vanilla essence, and rolled in dessicated coconut, but for the life of me I can't find the recipe anywhere.