I've been making these delicious little savory pies from the Moosewood Cookbook -- they're little circles of pastry dough stuffed with a mashed potato/ cabbage/ cheese mixture, folded over and baked. Alas, while they bake, the filling explodes and runs all over the tray -- sometimes it happens at the seam or side, sometimes from the top. I tried pricking the tops with a fork to create steam vents, to no avail. Am I over-stuffing them? They don't seem THAT full. Does anyone have any other suggestions? I've made two batches now and am growing frustrated. I don't mind a little leaking, but they're currently like Mount Vesuvius (see photo). Thank you so much!
Try lowering the temp a tad to give the steam a chance to escape. It is a fine line between soggy vs. crisp pastry.
And I agree that you are probably overstuffing them. Try drying out the mashed potatoes and cabbage.
You're not singing the ditty. See "Perfect Strangers" episode "Just Desserts" in which they make the legendary "Bibi-Babka." I am sure it is on YouTube but I don't know how to provide a link to that stuff.
Other than that...yup, overstuffed. Done it a few times myself.