https://www.cnet.com/news/behold-the-frozen-ghost-apples-of-michigan/

It's likely that the recent arctic blast from the polar vortex played a role in this unusual phenomenon. The sugar and acid content in fruits lowers the temperature at which they freeze by a few degrees, but the longer they're exposed to extreme cold, the worse the damage. 

Given that apples in the Great Lakes region were exposed to temperatures well below freezing for multiple days over the past couple weeks, it's no surprise some were turned to complete mush and simply ran out of the holes in the bottom of their icy shells.