A Boston cream pie is a cake filled with custard/cream and then frosted with chocolate. Not so much of a pie and more of a cake. It was created at the Parker House Hotel (now called Omni Parker House and Parker's Restaurant), which is also the home of Parker House Rolls and Boston Scrod.
Owners of the Parker House Hotel in Boston state that the Boston cream pie was first created at the hotel by Armenian-French chef M. Sanzian in 1856. The cake he created, called "Parker House Chocolate Cream Pie", consisted of two layers of French butter sponge cake filled with crème pâtissière and brushed with a rum syrup, its side coated with crème pâtissière overlain with toasted sliced almonds, and the top coated with chocolate fondant. (SOURCE)The Boston cream pie is the official dessert of Massachusetts. We went to the Omni Parker House to get a taste of the original Boston cream pie. While you can dine in the restaurant, you can also just get a small cake in their actual gift shop. That was all we needed. We got two forks and sat at the one small dining area and dug in.
This was quite tasty. I don't think a Boston cream pie is what I would originally go after if it were listed on a menu, but when one puts the time and effort into each individual detail - it all really comes together quite nicely.