[Thor Guldager]

Thanks, Jim!
But i was actually looking for a way to do a cube look similar to that of a dice. With rounded corners and sharper edges.
I did, however, find a fairly simple way to achieve this, after some playing around.
I just made a 1-by-1-by-1 cube editable, selected all points in point mode, applied a bevel with 1 subdivision to the points, and lastly extruding the inner polygons in the ways the drawing shows. This did the trick, if anyone else should stumble on this thread.