I made a cranberry and apple streudel dish for the first time a couple days ago, using frozen phyllo dough. The recipe said to bake at 375 degrees F for 35 minutes, or until it turned "golden brown", which I did. After taking it out of the oven and letting it cool, I cut the streudel only to find the inside still uncooked (the phyllo was not at all browned). I popped it back into the oven for another 15 minutes, noticing that the outside was browning nicely, and after that additional length of time, took it out, cooled it, and cut it. Still though, the inside phyllo was white in appearance and not cooked thoroughly.
How do I get a uniformly crispy streudel w/out burning or overcooking the outside? I used an olive oil cooking spray instead of butter on the phyllo layers so am wondering if that made a difference. Or do I need a higher oven temp?
Any advice will be much appreciated!