Classic Boston Cream Pie isn’t pie. It is cake with a cream filling and a chocolate ganache top. Apparently the reason it became known as pie was that bakers in 19th Century Boston made the cakes in pie pans.
There’s nothing wrong with cake, but often I find the cake version of Boston Cream Pie rather dry. Traditionally, the cake layers are sponge or pound cake. They should be a nice contrast to the creamy filling, at least in theory. However, in reality, that is not often the case. Instead, the cake is crumbly and overpowers the cream and chocolate.
So when I stumbled upon a SeriousEats’ version that was really pie, I was intrigued. I tried it and was impressed – up to a point. Good, but not great. The concept seemed better than the execution. After tweaking the filling and changing the pie crust from dough to a graham cracker crust, Boston Cream Pie finally became my ideal pie. Eureka!
Whether this version is an adaptation of the SeriousEats Boston Cream Pie, or is simply inspired by it, is a matter of semantics. What really matters is that it is pie, not cake. Gone are the dry cake layers. In their place, a graham cracker crust provides a moist and tasty base.
The ingredients are pure and simple. On top of the buttery graham cracker shell sit pastry cream filling and a chocolate ganache topping. The three parts play well together, crunchy at the bottom, smooth in the middle, and rich at the top.
For those who favor the traditional Boston Cream Pie, there is another way to look at this dessert. Don’t focus on the pedigree. Instead, think of it as a reverse chocolate cream pie. This pie turns that diner specialty on its head, substituting vanilla cream for chocolate filling and spreadable chocolate for a whipped cream top.
Boston Cream Pie Reinvented as Pie
A crunchy graham cracker crust, with vanilla pastry cream and a rich chocolate topping, this dessert is a crowd pleaser that is a lot simpler to make than it looks.
- 1 graham cracker crust
- 3 tablespoons unsalted butter, melted
- 3 tablespoons sugar
Filling - Vanilla Pastry Cream
- 2 cups whole milk
- 1 1/2 teaspoons vanilla
- 9 tablespons sugar (1/2 cup + 1 tablespoon)
- pinch kosher or fine sea salt
- 3 egg yolks
- 1/4 cup cornstarch
- 3 tablespoons unsalted butter, softened
- 3 ounces heavy cream
- 4 1/2 teaspoons light corn syrup
- 3 3/4 - 4 ounces dark chocolate, finely chopped
Crush the graham crackers and mix in the melted butter and the sugar. Spread over the pie pan and press down. See note below for link to pie crust recipe - must be baked and cooled before adding the filling.
Filling - Vanilla Pastry Cream
Stir the milk, vanilla, 1/4 cup of the sugar, and the pinch of salt together in a medium-large saucepan. Set aside.
In a separate medium bowl, whisk together the egg yolks, starch and the remaining sugar (1/4 cup + 1 tablespoon) until the mixture is thick and pale yellow, about 2-3 minutes.
Heat the milk, vanilla, sugar and salt mixture under a low light until the mixture simmers. Then remove from the heat and pour small amounts of the hot liquid into the egg yolks, starch, and remaining sugar in a stream, whisking after each addition. After you have added all the liquid to the egg yolks, starch, and sugar, pour the mixture back into the saucepan. Bring it back to a simmer, whisking constantly, and whisk for two more minutes after the first sign of bubbles.
Take the mixture off the heat and gently whisk in the softened butter, until the butter is completely absorbed into the custard.
Pour the custard into the cooled pie crust and press plastic wrap against the top. Let the filling cool for about 30 minutes, then refrigerate until well chilled, at least 2-3 hours.
Bring the heavy cream and corn syrup to a simmer over medium heat, stirring gently to combine the ingredients. Once the cream and corn syrup mixture simmers, pour it over the chopped chocolate (in a heatproof bowl) and leave those ingredients undisturbed for two minutes. At the end of the two minutes, stir them together until the chocolate is smooth. Refrigerate the ganache until you are ready to serve the pie. Once you are ready to serve it, microwave the ganache on a low setting and stir until it is a pourable consistency. Then gently pour it over the top of the pie and spread it out to the edges.
The process of slowly adding the heated milk to the eggs in the filling is called "tempering" the eggs. It prevents the eggs from scrambling, which would happen if you suddenly added all of the hot liquid to the cold eggs.
If you can find it choose heavy cream over whipping cream for the topping. Here is why.
You can make the chocolate topping (called ganache) days or even weeks ahead of time and freeze it, well wrapped. When defrosting it in a microwave (or warming it after refrigeration) do it slowly at a low setting, stirring frequently.
The butter pictured among the ingredients is partly for the graham cracker crust. Here's my crust recipe. If you prefer a slightly less sweet crust with this rather sweet pie, just leave out the sugar in the crust and use only graham crackers and butter.