Boston Cream Pie Ice Cream Sandwiches
- Pastry cream ice cream
- 1 1/2 cups whole milk
- 2 teaspoons vanilla extract
- 2 tablespoons all-purpose flour
- 1 tablespoon cornstarch
- 2/3 cup granulated sugar, divided
- 1/4 teaspoon fine sea salt
- 3 large egg yolks
- 1 1/2 cups chilled heavy cream
- Vanilla whoopie pies
- 2 1/4 cups all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon fine sea salt
- 4 ounces (1 stick) unsalted butter, at room temperature
- 3/4 cup granulated sugar
- 1/4 cup packed light brown sugar
- 3 large eggs
- 2 teaspoons vanilla extract
- 2/3 cup whole milk
- chocolate ganache (about one cup), for topping
For the pastry ice cream:
Prepare an ice bath by filling a large bowl with ice cubes and 1 to 2 cups of water. Place a medium bowl fitted with a fine strainer inside the ice bath.
In a medium saucepan, combine the milk, vanilla, flour, cornstarch, 1/3 cup sugar and salt. Set over medium heat, stirring occasionally, until the mixture is warm and tiny bubbles form around the edges of the saucepan, about 3 minutes.
In a medium bowl, whisk the remaining 1/3 cup sugar with the egg yolks until completely smooth. Carefully whisk half of the warm milk mixture into the egg yolks, one ladleful at a time, until the egg mixture is warmed. Whisk the egg-milk mixture back into the saucepan. Cook the mixture over medium heat, stirring constantly with a wooden spoon, until the mixture is thick enough to coat the back of the spoon and registers around 175°F on an instant-read thermometer, about 5 to 7 minutes. Be careful not to boil the mixture.
Immediately strain the mixture through the fine strainer into the prepared ice bath. Cool the custard in the ice bath until it reaches room temperature, stirring often. Press plastic wrap against the surface of the custard and refrigerate until chilled, about 4 hours or up to 1 day.
Once the mixture is chilled, stir in the heavy cream. Pour the mixture into an ice cream maker. Freeze according to the manufacturer’s directions. Transfer the ice cream to an airtight container, press plastic wrap against the surface of the ice cream, and freeze until it is firm and the flavor is ripened, at least 4 hours.
For the vanilla whoopie pies:
Preheat the oven to 375°F. Line baking sheets with parchment paper or silicone baking mats.
In a medium bowl, whisk together the flour, baking powder and salt.
In a large bowl, use an electric mixer to beat the butter and sugars on medium-high speed until smooth and well combined, about 1 to 2 minutes. Add the eggs, one at a time, until combined. Add the vanilla. On low speed, gradually add half the flour mixture, the milk and the remaining flour mixture and beat until combined.
Using a spoon or spring-loaded scoop, drop the batter in 2-tablespoon rounds onto prepared baking sheets, spacing 2 inches apart.
Bake for about 8 to 10 minutes, or until the edges are set and the tops spring back when touched. Let cool on baking sheets for 5 minutes before removing to wire racks to cool completely. Freeze the whoopie pie halves until frozen, at least 1 hour.
Whoopie pie halves can be stored in airtight containers in the freezer for up to 1 month.
Top one frozen whoopie pie half with a scoop of ice cream. Place another whoopie pie half on top of the ice cream and gently press down to form a whoopie pie sandwich. Pour 1 tablespoon of the ganache over the sandwich.
Place the sandwich on a baking sheet or in a flat container that will fit in the freezer. Repeat for the remaining cookies. Place the ice cream sandwiches in the freezer and chill until the chocolate ganache has set, about 30 minutes.
Serve or wrap sandwiches in plastic wrap and return to the freezer to store for up to 1 week. Let sit at room temperature before serving.