Not the Mickey/Fantasia/Nic Cage Sorcerer’s Apprentice, but based on a novel called Krabat: The Satanic Mill, recently filmed again as a post-Twilight live-action feature. Second-to-last film by Zeman, who died in ’89. I’ve only seen one of his earliest shorts, though I’ve been meaning to watch his Baron Prásil for a long time now.
A poor kid named Krabat ends up at an enchanted mill run by an evil one-eyed wizard, with a staff of boys. Every year the wizard challenges the oldest to a duel, beats him by cheating, and then buries him in the grave the boy dug earlier that day. But Krabat has found a reason to live, an enchanting young girl whom he secretly visits, so he teams up with another boy to learn the magical secrets to defeat the evil wizard.
I was not bowled over by the animation at first, which looked like cut-outs with hinged joints, but as the story sucked me in and I started noticing subtle details, like the odd timing of the transformation scenes and the apparently live-action smoke, fire and water effects, I gained a greater appreciation for the movie by the end.