What are potential causes of splitting in baked pie dough?
Is it really "splitting," or is it just not tough enough to support the contents of those delicious looking little hand-pies there? It looks like it might be great (tender and delicious) for a pie in a pie-pan which doesn't need so much structural strength.

I think this dough is too short &amp; delicate and/or rolled out too thin for this purpose. It would provide more support if you either added a little more flour and water (proportionately -- in other words: less shortening), worked it a little more to develop a little tougher gluten, or maybe simply rolled it into a little bit thicker sheet. I bet it won't be quite as tasty if you do that, but might be mechanically a little more effective.

Also, I'm not 100% clear on the sizes in the photo, but perhaps the dough could work better as-is if the pies were made a little smaller, ... if that is feasible at all. Since I guess pies scale like other things; the bigger they are, the less delicate they can afford to be.