Boston Cream Pie
Ingredients
- 1 recipe hot milk sponge cake (below)
- 1 recipe pastry cream (below)
- 1/3 cup (80 ml) heavy whipping cream
- 3 Tbsp Dulce de leche (store bought)
Hot Milk Sponge Cake
- 2 cups plus 1 Tbsp (230g) cake flour
- 2 tsp baking powder
- 1 / 2 tsp kosher salt
- 3 eggs at room temperature
- 2 egg yolks at room temperature
- 11/2 cups (300g) granulated sugar divided
- 3/4 cup (175ml) whole milk
- 2 Tbsp mild-flavored oil such as vegetable oil
- 1 Tbsp vanilla extract
Pastry Cream
- 2 cups (480ml) whole milk
- 1 / 2 cup (100g) granulated sugar
- 1 /4 cup (55g) unsalted butter
- 1 pinch kosher salt
- Seeds scraped from 1/2 vanilla bean or 2 tsp vanilla extract
- 3 Tbsp cornstarch
- 2 eggs at room temperature
- 4 egg yolks at room temperature
Shiny Chocolate Ganache
- 1/2 cup (120ml) water
- 1 cup (200g) sugar
- 1/3 cup (40g) Dutch-processed cocoa
- 1/4 tsp kosher salt
- 1/3 cup (80ml) heavy whipping cream
- 4 oz (112g) bittersweet chocolate finely chopped
Instructions
Hot Milk Sponge
- Preheat the oven to 350°F / 175°C. Line the bottoms of two 9-inch / 23cm cake pans with greased parchment, but leave the sides of the pans untouched. The cakes need to cling to the ungreased pans to rise properly.
- In a large bowl, whisk together the flour, baking powder, and salt and then sift back into the bowl. Set aside.
- In a stand mixer fitted with the whisk attachment, whip the eggs and egg yolks on high speed. Once the eggs are well combined and starting to foam, about 1 minute, turn the speed to medium-low and sprinkle 3 ⁄4 cup / 150g of the sugar slowly over top. Turn the speed to high and let it whip for about 5 minutes.
- While the eggs are whipping, in a small saucepan over medium heat, bring the milk, oil, and remain- ing 3 ⁄4 cup / 150g sugar to a boil. Turn off the heat and stir in the vanilla. Once the eggs are light in color and thick, they should be able to form a ribbon of batter that sits on top of the egg foam for a few seconds when you lift the whisk out of the foam. Turn the mixer speed to low, slowly add the boiling milk mixture, and then add the flour mixture, a few tablespoons at a time, scraping down the bowl several times.
- Immediately pour the batter into the prepared pans and gently run a spatula through the batter to pop any large air bubbles.
- Bake until a tester comes out clean, 15 to 20 minutes. Let the cake cool completely in the pans. Run a knife around the edge before turning out onto serving plates. The cakes can be served simply sliced with dollops of lemon curd.
Pastry Cream
- In a medium saucepan over medium heat, combine the milk, 1 ⁄4 cup / 50g of the sugar, butter, salt, and vanilla; bring to a gentle boil; and then remove from the heat.
- In a medium bowl, whisk together the cornstarch and remaining 1 ⁄4 cup / 50g sugar. Add the egg and egg yolks and whisk into a smooth paste.
- Whisk enough of the hot milk, a little at a time, into the egg mixture until it is warm to the touch. Once the eggs are tempered, pour the mixture back into the remaining milk in the pan.
- Return the saucepan to medium-high heat and bring the mixture to a boil; continuously whisk for 3 minutes more or the pastry cream will separate once it cools.
- If there are any lumps in the pastry cream, strain it through a fine-mesh sieve into a shallow container and cover with plastic wrap, pressed directly onto the surface, to prevent a skin from forming.
- In a large bowl, add enough ice cubes and cold water to create a bath for the container to sit in without the water breaching the sides.
- Set the container in the ice bath or place in the freezer until chilled, about 15 minutes before using. Or transfer to an airtight container and store in the refrigerator for up to 3 days.
Shiny Chocolate Ganache
- In a medium saucepan, bring water, sugar, cocoa, and salt to a simmer and cook over medium-low heat until the sugar is melted, about one minute. Add the heavy cream and cook, stirring continuously until the mixture is reduced by about 1/3 the volume. It will be the consistency of Hershey's chocolate syrup.
- Remove from heat, add the chopped chocolate, and swirl the pan to submerge the chocolate. Allow to sit for 2 minutes and then gently whisk the ganache until smooth.
- Loosely cover and allow to come to room temperature before pouring over the cake. (Pro tip) The mixture should be thick but pourable. If it is too thin, chill the mixture for about 5 minutes or until it is thick enough to cling to the cake. If it sets up too much, place it over low heat and soften it very slightly, just a few seconds at a time.
Assembly
- Place one cake layer on a serving plate.
- In a medium-sized bowl, using a handheld mixer or whisk, whip the heavy whipping cream and Dulce de Leche to stiff peaks.
- Stir the pastry cream, then mix in one-third of the whipped cream to lighten. Fold in the remaining whipped cream.
- Using an offset spatula, spread all of the pastry cream over the cake; making sure not to go quite to the edge. Place the next cake layer over the pastry cream. Gently press down on the cake to make sure it is sitting snugly on the pastry cream. If the pastry cream goes beyond the edge, clean it up with a metal decorating spatula. Cover with plastic wrap and refrigerate for at least 1 hour (up to 8 hours) to set the pastry cream in place.
- Pour the shiny ganache over the top of the cake, starting in the center and stopping just as it drips over the edge.
- Refrigerate the cake until the ganache sets, about 30 minutes, then serve right away.