Boston Cream Pie

Boston cream pie originated in the Parker House hotel in Boston in the mid-1800s and is the official state dessert of Massachusetts. And contrary to its name, it’s not actually a pie. It’s silky pastry cream sandwiched between layers of vanilla sponge, which is then topped with a rich chocolate glaze.

Boston cream pie was the Technical Bake for Cake Week in Season 7 of The Great Canadian Baking Show.

Boston Cream Pie

Ingredients

Cake:

• ¾ cup 3.25% milk
• ½ cup (113 g) unsalted butter plus extra for greasing, room temperature
• 3 eggs
• 1 cup (200 g) sugar
• 1¾ cups (255 g) all-purpose flour
• 1¾ tsp baking powder
• 1 tsp kosher salt
• 1 tsp vanilla

Pastry Cream:

• 1 cup 3.25% milk
• 1 cup 35% cream
• ¾ cup (150 g) sugar, divided
• 1 vanilla bean
• 4 large egg yolks
• 3 tbsp (21 g) cornstarch
• ½ tsp kosher salt
• 1 tbsp (14 g) unsalted butter, room temperature

Vanilla Soak:

• ½ cup water
• ½ cup (100 g) sugar
• 1 tsp vanilla extract
• ¼ tsp kosher salt

White Icing:

• 1 cup (125 g) icing sugar
• 3 tbsp 35% cream

Chocolate Glaze:

• ¼ cup 35% cream
• 113 g semi-sweet chocolate
• 1 tsp vegetable oil
• 1 tsp white corn syrup
• ¼ tsp kosher salt

Preparation

Cake:

Heat oven to 325 F. Grease an 8-inch round cake pan (3 inches deep) with softened butter, and line with a round of parchment paper.

Fit a stand mixer with the whisk attachment. Beat eggs and sugar on medium speed until pale, thick and doubled in volume, about 8 minutes.

Meanwhile, whisk together all of the dry ingredients in a medium bowl.

In a medium saucepan over medium heat, combine milk and butter, and heat until the butter is melted. Remove from heat and set aside. 

With the mixer on low speed, add the dry ingredients, ¼ cup at a time, until fully mixed. Scrape down the sides of the bowl with a rubber spatula and mix on low until combined, another 10 seconds. 

Add vanilla extract to the pot of warm milk. With the mixer on low speed, slowly pour the milk mixture down the inside of the bowl and mix until fully incorporated into the batter. Don’t pour the hot milk directly on top of the batter; it will deflate.

Pour the batter into the prepared cake pan and spread evenly. Bake until the top of the cake looks dry and a skewer inserted in the centre comes out clean, 45 to 50 minutes. The cake should be golden brown with a domed top.

Cool the cake in the tin for 5 minutes, then run a paring knife around the edge and turn it out onto a wire rack. Flip it right side up, and chill to cool completely. 

Pastry Cream:

In a medium saucepan, combine milk, cream and half of the sugar. Cut the vanilla bean in half lengthwise and scrape out the seeds. Add the vanilla pod and seeds to the saucepan, stir with a wooden spoon, and bring to a simmer over medium heat. 

In a large bowl, whisk the remaining sugar, egg yolks, cornstarch and salt until combined. Whisk about ½ cup of the hot milk into the egg yolk mixture. While whisking, slowly pour the tempered yolks into the saucepan, and place over medium heat. Use tongs to remove the vanilla pod, and discard. 

Stir the mixture with a wooden spoon as it starts to bubble. When the mixture thickens, switch to a whisk. Whisk the pastry cream until it comes to a low boil, 2 minutes. Whisk in the butter. 

Pour the pastry cream through a fine-mesh sieve set over a quarter-sheet pan. Cover the surface of the pastry cream with plastic wrap. Chill in the fridge until ready for assembly. 

Vanilla Soak:

In a small saucepan, combine sugar, water, vanilla extract and salt. Bring to a boil over medium heat. Remove from heat and set aside.

White Icing:

Add the icing sugar to the bowl of a stand mixer fitted with the whisk attachment. Pour in the cream and start mixing on low speed, increasing the speed as the icing thins out. When the icing is smooth, transfer it to a small piping bag and set aside.

Assembly:

Whisk the chilled pastry cream until smooth, and then transfer it to a piping bag fitted with a large round tip.

When the cake is cool to the touch, use a serrated knife to carefully slice the cake into three even layers.

Place the bottom layer of cake onto an 8-inch cake board, cut side up. Brush it with half of the cooled vanilla soak. Evenly pipe half of the pastry cream onto the cake, and place the middle layer on top. Repeat the steps with the rest of the vanilla soak and pastry cream. Place the domed layer on top. Chill the assembled cake while you make the chocolate glaze. 

Chocolate Glaze:

In a small saucepan, heat the cream to a bare simmer. 

In a medium bowl, combine the chocolate, oil, corn syrup and salt. Remove the saucepan from the heat, and add the hot cream to the chocolate mixture. Allow the cream to start melting the chocolate, about 2 minutes, then gently whisk until the glaze is smooth and shiny. Pour the glaze on top of the cake and spread evenly with a small offset spatula, allowing the glaze to run over the edge and drip slightly onto the sides.

Pipe about five straight lines of white icing on top of the chocolate glaze, from one side of the cake to the other. Drag a toothpick back and forth across the lines to create a feathering effect. 

Makes one cake