This idea would be a very hard draw. I did some test drawings to see if it was even possible, and I think might be possible, but I'm not totally sure if it can be designed.
The idea is to have a 3d puzzle, that is a black cube. The entire inside volume of the cube is made of puzzle pieces, that are all totally black. These puzzle pieces are 3d modified shapes of the normal shaped 2d puzzle pieces, bent and 3d enhanced, but they look recognizable to the eye as puzzle pieces.
The outside surface of the black cube will give the usual edge pieces to find. However the inside pieces might hard to fit. Which is actually the point. Maybe like a puzzle rubrics cube? All the pieces are printed separately so the puzzle would print easy
The puzzle would have to interlock and stay together, so there would be a special order to put in the pieces and perhaps a mildly tricky way to assemble it.
This idea would be hard, but maybe not be too hard if there were 10 or 12 pieces, but with 50 pieces it would probably become too hard to draw and take too long to be practical. Not an easy idea.