If you just want the pie recipe and don't want to read a couple paragraphs of backstory and research, click here.
When I first moved to Pittsburgh in 2007, there was a restaurant in Squirrel Hill roughly across the street from the Giant Eagle called Gullifty's. The two things they were most famous for were their expansive menu and their desserts. I don't often bother ordering dessert at restaurants, given that I don't really need the extra calories and a lot of restaurant desserts are just frozen stuff from Sysco or whatever, but their pies were genuinely worth it. All the dessert items I ever tried there were excellent, but my favorite was their peanut butter truffle pie. The Oreo cheesecake was a close second, I'll post my take on that recipe sometime in the future.
In 2013, the owners of Gullifty's decided they had enough of running a restaurant and closed down, selling the building to a day care. I always liked to bake, and tried to make my own peanut butter pie by adding peanut butter to the cheesecake recipe I've been making since I was in high school and adding a chocolate topping. While it was good, it wasn't quite the pie I remembered, which had a lighter filling and something different about the crust.
Fast forward 10 years to 2023, and I decided to do some research and try again. First, I found a copy of a Gullifty's menu that was still online that described the pie as "Vanilla wafer and peanut crust, a layer of chocolate truffle, peanut butter mousse, whipped cream and peanuts." Ah, peanut butter mousse as opposed to peanut butter cheesecake, and the crust was vanilla wafers and peanuts, not graham crackers. A bit more searching revealed a Tribune-Review article from 2012 which listed a recipe for a macadamia truffle tart provided by the owner, Matt Hastie. While a macadamia truffle tart wasn't quite what I was looking for, this recipe contained a chocolate truffle recipe that stands a good chance of being the same one they used in their other desserts. With this information in hand, I came up with the recipe below. I can't promise it's exactly the pie you would have gotten at a restaurant that closed over a decade ago, but it's a tasty dessert that's close enough to satisfy my memories of the past.
This recipe has several parts, but doesn't require any baking. You'll need a food processor and a mixer (or a strong arm and a lot of patience). You'll be making the pie crust, the peanut butter mousse, the chocolate truffle filling, and some whipped cream to top it.
Grind vanilla wafers and peanuts in a food processor. You want fairly small crumbs, about the consistency of corn meal. The peanut bits won't be as small as the cookie bits, this is fine.
Melt the butter in a mixing bowl. You want it to be completely liquid.
Stir in the cookie crumb/peanut mixture thoroughly.
Split this evenly between two greased pie pans and press it with a spoon to pack it into the pan, making sure to get crust into the sides of the pan.
Refrigerate for at least a half hour before filling.
This recipe was borrowed from Taste of Home and consists of three parts: Making unsweetened whipped cream, blending peanut butter with sugar and softened cream cheese, and carefully folding these two items together to make the mousse.
Beat the whipping cream and vanilla in a mixer (or by hand with a wire whisk if you choose) on medium to high speed until stiff peaks form. Stiff peaks means that when you take the beaters out of the mixer or lift up your wire whisk, the points of the cones that you'll see should stay straight up and not curl over. Put the whipped cream into a bowl and store it in the refrigerator while you do the next step.
Beat the cream cheese and sugar together until smooth. The result should be something like cream cheese frosting. Once this is done, beat in the peanut butter a few spoonfuls at a time until thoroughly combined. The result will look a bit like wet sand because of the peanut butter.
Whipped cream is cream with air mixed into it. If you're too aggressive mixing it with the peanut butter mixture you'll pop the air bubbles and be left with a filling that's too runny. The trick is to spoon a small amount (maybe 1/2 cup or so) of whipped cream into the peanut butter mixture and gently fold the peanut butter mixture into it until mostly combined, then add more whipped cream and repeat. The final product will be about the consistency of mayonnaise. If we were going to serve this on its own we could put it in a piping bag, fill dessert cups with it, and chill it for a few hours before serving, but since we're making a pie it will be easier to spread the filling in at room temperature.
Take the chilled crusts out of the refrigerator, spoon an equal amount of mousse into each crust, and spread it out evenly. If you're careful you can shake the pie pan to spread it out. It doesn't have to be perfectly smooth since the chocolate truffle on top will cover up the imperfections. Once that's done, chill the pies for at least an hour before adding the chocolate truffle topping. Trying to add the topping too soon will likely result in a puddle of chocolate in the center and some melted mousse, which while still tasty, won't look that impressive on a plate.
Combine all the ingredients and gently heat in a double boiler. Mix well until smooth. If you don't have a double boiler, use a mixing bowl over a pot of simmering water. Remove the chilled pies from the refrigerator, and gently drizzle the liquid truffle onto each pie, carefully rotating and tilting the pies to distribute the truffle evenly. Put the pies back in the refrigerator and let them chill for another hour.
I don't remember exactly how Gullifty's garnished their pies but I think they were topped with whipped cream and some chopped peanuts, so that's what I've done.
Similarly to the previous whipped cream recipe, mix all ingredients together and whip on medium to high speed until stiff peaks form.
Chop another 1/4 cup of the unsalted roasted peanuts. You don't need to turn them into peanut flour, you just want them to be about the size of crushed peanuts you'd get on top of an ice cream sundae.
Decorate the pies however you wish. I usually put whipped cream in a piping bag and try to make a nice pattern of whipped cream florets on top of the pie, and then sprinkle on the chopped peanuts.
If all goes well, the end result should look something like the photo below. I'll take some more photos of various steps in the process the next time I make this recipe.
