triple chocolate cheescake in philly
If it had a chocolate wafer crust with what looks like a cream ganache on top it sounds to me you had a slice from a recipe by Myra Chanin. She's a local food writer who did a cookbook called:" Mother Wonderfuls Cheesecakes and Other Goodies". It's been in and out of print. Last time I saw her byline was in "Philly Style" magazine. Contact her througth the mag and maybe she'll give you the recipe. Better yet, try to find and buy her book. The recipes are consistant and fool proof.