Why on earth is this cake called a pie? According to What’s Cooking in America, which details the history of the dessert, the differentiation between pie and cake in nineteenth-century America was very fluid. Apparently, more people owned pie pans than cake pans, resulting in a tradition that produced the American pudding-cake pie. The Parker House Hotel in Boston claims credit for the creation of Boston Cream Pie. It was served at the hotel’s opening in 1856 and was the invention of its French chef, who is given different names—either Sanzian or Raelyn. In any case Boston Cream Pie was declared the official dessert of Massachusetts in 1996.
The combination of cake, custard, and chocolate is truly a marvelous taste. I’ve often felt that the traditional recipes for this dessert, which call for a heavier cake and a thick pastry cream, are bit too much for modern tastes. Thus I created this much lighter version, which uses a airy non-butter sponge cake and an extremely light Bavarian cream for the custard.
The Custard
Because the Bavarian cream needs to chill and partially set, it’s best to begin by making the custard first. Chill a bowl and beater. Soften the gelatin in 1 tablespoon of cold water. Bring the milk to the simmer in a 1-quart saucepan.
Softening the gelatin.
Beat the egg yolks with the cornstarch until smooth. Very gradually add the sugar while beating. Continue to beat until a ribbon forms when the batter is dropped from the beater.
Beat sugar into egg yolks.
Gradually add the simmering milk to the egg yolks, beating constantly.
Add milk to beaten yolks.
Pour the mixture back into the saucepan. Cook over low heat, stirring constantly with a whisk until the mixture reaches 165° on a thermometer or until the mixture coats the back of a wooden spoon. Be very careful not to let the mixture boil or it will curdle. Off the heat, stir the softened gelatin into the hot mixture until it is thoroughly dissolved. Return the mixture to the bowl.
Place the bowl of custard in a larger bowl filled with ice, stirring constantly until the cream reaches room temperature. Remove from the ice. Stir in the vanilla. In the chilled bowl, beat the heavy cream until medium peaks are formed. Place the custard mixture in the bowl of ice again, stirring constantly with a rubber spatula until it just begins to thicken. Do not let it set. Remove from the ice and stir in 1/3 of the whipped cream with the rubber spatula. Fold in the remaining whipped cream. Refrigerate for about 3 hours or until the cream is of spreading consistency—neither runny nor completely set.
The Cake
Preheat oven to 350°. Butter and flour an 9-inch cake pan. In a large bowl, beat the egg yolks until thickened. Gradually beat in 3/4 cup of the sugar, then the vanilla, and continue to beat until the mixture forms a ribbon. Beat the egg whites until foamy and sprinkle on the cream of tartar. Continue to beat until soft peaks are formed. Gradually beat in the remaining 1/4 cup of sugar until stiff peaks are formed.
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Stir in 1/3 of the beaten egg whites into the yolk mixture with a rubber spatula. Sprinkle 1/3 of the flour through a sieve into the batter and fold in carefully.
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Fold in the remaining 2/3 egg whites and flour, alternately by thirds. Pour the batter into the prepared cake pan and bake in the middle level of the oven for about 35-40 minutes.
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When a cake tester comes out clean, remove the cake to a wire rack, and let cool for ten minutes. Invert onto the rack and let cool completely. When ready to assemble, cut into two equal layers.
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Optional Sugar Syrup
Although not completely necessary, I like to brush the cake with a rum-flavored sugar syup. It keeps the cake moist in the refrigerator, particularly if you are not eating the entire cake at one sitting. Combine the sugar and water in a saucepan. Bring to a boil, stirring occasionally, until the syrup is clear. Let cool and add the optional liquer.
The Chocolate Glaze
Chop the chocolate finely and place in a bowl. Heat the heavy cream with the corn syrup just to the boil, stirring to keep it from boiling over. Reduce the heat and simmer for at least 2 minutes continuing to stir. Gradually pour the hot cream over the chocolate, stirring constantly with a whisk. Cool until it just begins to thicken.
Assembly
If using the sugar syrup, brush it over the cut side of both layers of the cake. Spread the custard filling over the bottom layer of the cake.
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Carefully place the top layer over it. Pour the glaze over the cake and spread to cover the top. If it runs down the sides, that’s fine. Chill the cake for at least 2 hours.
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Remove the Boston Cream Pie from the refrigerator at least 15 minutes before serving.
To print or download the recipe, click here.