Probably, you already love Philadelphia Butter Cake. I mean, the title includes the words "butter" and "cake", so pretty much no matter where it's from, it's going to be lovable, right? In my opinion, we owe Philadelphia bigtime for giving us (and by "us" I mean, like, everyone in the world) the gift of this cake.
But, you may be wondering, what exactly is it?
Judging by the picture and the name, you might be tempted to think that Philadelphia Butter Cake, a rich, buttery cake with a gooey center, which served in bar form, is similar to Gooey Butter Cake, a St. Louis specialty. But you're not quite right: while they have some similar characteristics, I'd call them more "cousins" than "twins".
Likewise, you wouldn't want to confuse it with a simple "Butter Cake", or to expect a buttery yellow cake to be your result--there is really no frosting necessary with the Philadelphia version, and if you baked it expecting a layer cake, you'd be disappointed for sure.
But let's go back to the Gooey Butter Cake. If you already know what that is, you have an idea of what you'd be up against with the Philadelphia Butter Cake. But the important differences? As I see it,
A. There is yeast in the "crust" part of the cake.
B. There is no cream cheese in the soft and gooey middle section; it is made of butter, more butter, a bit of flour, sugar, eggs, milk, and flavorings.
C. The top forms a lightly soft crusty texture, which I found more pronounced than with a Gooey Butter Cake.
The cake is sometimes referred to as "German Butter Cake", which leads me to believe that it is probably an American adaptation of a German cake, adapted in the new world to reflect the ingredients available.
The Philadelphia Butter Cake pictured in this post was obtained at the Flying Monkey Patisserie in the famed Reading Terminal Market, where, when ordering, I said "I'll have the buddah cake. Buddah". You know, to be funny.
The cake was very, very good. It's so rich that it makes you want to cry, and has a touch of saltiness which complements the sweet, that makes you want to keep eating more and more. Their version had a more shortbread-y crust, so it may not be completely traditional, but it was totally tasty. I want more right now, in fact.
They also carry the cake at Town Crier Bakery and Bredenbeck's (I have tried this version, and it's very good). I also hear there's a fantastic version at Haegle's, which is famous for the stuff.
Here's a great blog post featuring a recipe for Philadelphia Butter Cake, including a step by step tutorial.