This is the best chocolate pie I have made/eaten in my life. The trick is that you must beat the ingredients for 10 minutes or the pie will not be the consistancy you would like. It sounds like the one you have described. My father got it from a diner owner who would not tell him the ingredients until the day she retired 40 years after opening the diner. It's worth it.
I grew up near Pennsylvania and Pennsylvania Dutch country, I spent a summer during college helping out at an Amish dairy near Lancaster. This recipe was given to me by one of the women there.