How to Make Boston Cream Pie | Step-by-Step

Did you know that Boston Cream Pie (that wondrous “pie in cake’s clothing”) was invented at the Parker House Hotel in Boston? To learn more history and trivia, head on over to the 2015 Boston Cream Pie | Recipe with a History Yankee feature, but if you’re also wondering how to make Boston Cream Pie, with lots of step-by-step photos, you’ve come to the right place!

Before I got this recipe down I must confess that there were a lot of BCPDs (that’s Boston Cream Pie Disasters) in my kitchen during the testing phase, including a memorable version which had enormous cake layers and a runny filling. The biggest problem was the pastry cream, which I couldn’t get to firm up enough so it wouldn’t ooze out (sometimes slowly, sometimes violently) the moment I placed the second cake on top. Finally, after a half dozen tries, I asked Senior Food Editor Amy Traverso for input, and she suggested adding a small amount of plain gelatin to help with stability. Thankfully, it worked. You know the Hallelujah Chorus from Handel’s Messiah? It sounded something like that in my kitchen that warm September day when I finally had a good, sturdy cream. Ahhh, memories. Pastry cream dilemma solved, all that was left to do was melt some chocolate glaze and call it a day, which I did. Are you ready to see how it’s done? Here’s how to make Boston Cream Pie.

HOW TO MAKE BOSTON CREAM PIE | Step-by-Step

STEP 1: PASTRY CREAM

Boston Cream Pie is made up of pastry cream, sponge cake, and chocolate glaze. First, let’s make the pastry cream so it can chill and firm up in the fridge. When I could, I tried to make the pastry cream the night before so it would be perfect by the time I needed it, but if you can’t (or forget) to do that, a few hours should be enough. Warm 1 1/4 cups of milk (not to worry, the full recipe will be linked at the end) along with the sugar, gelatin, and salt over medium heat to barely a simmer. Meanwhile, whisk together the yolks, cornstarch, and the final 1/4 cup of milk. Pour one cup of the hot milk mixture into the egg mixture and whisk to combine, then strain the egg mixture back into the remaining hot milk.

Next, whisk the egg/milk mixture constantly over medium heat until thickened and bubbling in the center (a silicone-covered whisk was handy here), then remove and strain again into a medium bowl before adding the butter and vanilla.

Whisk until smooth, then cover with plastic wrap, pressing the wrap directly onto the surface to prevent a skin forming. Chill the pastry cream thoroughly, preferably overnight.

STEP 2: CAKES

Next, make the sponge cake. Preheat the oven and prepare two 8-inch cake pans by lining them with parchment. In a large bowl, cream butter and sugar with an electric mixer until light and fluffy. In another bowl, whisk together flour, baking powder, and salt. Add the eggs to the butter mixture one at a time, then add one-third of the dry ingredients to the butter/egg mixture and stir until just moistened. Add one-third of the milk and repeat this sequence until all ingredients are combined. Stir in vanilla.

Divide batter between the prepared cake pans and bake for 25-30 minutes, rotating halfway through, or until tops are lightly golden and a toothpick inserted into the center comes out clean. Allow to cool in the pans for ten minutes, then remove and transfer to wire racks to cool completely. Note that these cakes are a bit more “old fashioned” than the moist, buttery box-mix cakes we’re so used to today. If you prefer a moist, sweet cake feel free to swap ours with your favorite recipe for butter/yellow cake. We won’t tell (and based on the reviews we read online while researching BCP, it’s what many people do anyway).

Once the cakes have cooled and the pastry cream is chilled (giving it a few stirs with a spoon should show a thick, slightly gelatinous pudding), it’s time to build the cake.

STEP 3: ASSEMBLE

To assemble Boston Cream Pie, place one cake top-side down onto a large cake plate. If you want a “clean” plate for serving, put a few strips of parchment under the sides of the cake first to catch the drips of chocolate, but where’s the fun in that? If the cake has a domed top, use a serrated knife to gently remove the dome so the cake will sit flat on the plate. Spoon the chilled pastry cream onto the center of the cake and spread evenly until the cream just barely reaches the edge of the cake.

Gently place the other cake dome-side up on top of the pastry cream. Store the cake in the refrigerator while you make the glaze. Now THIS is what I had been waiting for — smooth pastry cream with no oozing!

STEP 4: GLAZE

To make the chocolate glaze, combine the chocolate chips, cream, and corn syrup in a medium saucepan over medium heat, stirring occasionally. When completely melted, remove from heat and stir in the vanilla.

Finally, pour the glaze over the top of the cake, allowing it to drizzle down the sides. Some recipes call for a thick, almost frosting-like glaze, but ours is thin, shiny, and sure to dazzle with lots of showy drips down the side. When the glaze has firmed up a bit, the cake is ready to serve.

STEP 5: CUT & ENJOY

I’ll warn you that when you’re dealing with an “open sided” cake with a wobbly filling, the best way to cut it is with a long, sharp knife in quick, firm strokes. Hesitate mid-slice and you may find yourself with a hand covered in pastry cream. Still tasty, but not always pretty.  Store any leftovers in the refrigerator.