Boston Cream Whoopie Pies

Yield:

20 whoopie pies

For the pastry cream

Instructions

First, make the pastry cream: Fill a large mixing bowl with ice and cold water and set aside.

Add the milk to a medium saucepan and warm over medium heat until just simmering.

While the milk heats, whisk together in a medium bowl the egg yolks, sugar, and cornstarch (it will seem dry and crumbly at first but keep whisking!) until fluffy and pale yellow. Set aside.

When the milk has reached a gentle simmer, remove from heat and, while constantly whisking, pour half of the milk into the egg mixture in a slow, steady stream. Add the egg-and-milk mixture back into the saucepan and return to medium heat to cook while continuously whisking. The mixture will be frothy at first but will begin to smooth and thicken. When the first bubbles appear, set a timer and whisk for 1 additional minute. Remove from heat, whisk in the butter and vanilla extract, and immediately pour the pastry cream through a fine mesh sieve into a medium bowl using a flexible spatula to press the cream through the sieve.

Place plastic wrap directly on the surface of the pastry cream to prevent a skin from forming and place the bowl in the ice bath for 30 minutes. Remove from the ice bath and place the pastry cream in the fridge until completely chilled.

For the cakes

Ingredients

2½ cups (300 grams) all-purpose flour
1 cup (120 grams) sugar
1 teaspoon baking powder
½ teaspoon baking soda
1 cup buttermilk, room temperature
½ cup (1 stick) salted butter, melted and slightly cooled
1 egg, room temperature
2 teaspoons pure vanilla extract

Instructions

Next, make the cakes: Preheat your oven to 350°F and line two baking sheets with parchment paper.

In a medium bowl, whisk together the flour, sugar, baking powder, and baking soda. Set aside.

In a separate bowl, whisk together the buttermilk, melted butter, egg, and vanilla extract. Add to the dry ingredients, whisking just until smooth.

Use a 1-tablespoon cookie scoop with a release lever to scoop the batter onto the baking sheets, spacing the portions 2 inches apart. Bake, rotating the sheets halfway through, for 6 to 8 minutes or until set and just lightly golden around the edges. Cool on the sheets for 5 minutes and then transfer to a wire rack to cool completely.

For the ganache

Ingredients

4 ounces (115 grams) semisweet chocolate, finely chopped
¼ cup heavy cream

Instructions

Then, make the ganache: Combine the chocolate and heavy cream in a heatproof bowl and place in a microwave for 20 to 30 seconds. The chocolate should be about 75 percent melted. Remove from the microwave and whisk until smooth and glossy. Set aside to cool slightly.

Remove the pastry cream from the fridge, uncover, and whisk until creamy. Arrange half of the cakes flat side down and spoon a small amount of ganache on the top of each cake, smoothing it with the back of a spoon. Allow several minutes for the chocolate to set. Arrange the remaining cakes flat side up and spread with 1 tablespoon of pastry cream per cake. Top each with the flat side of a ganache-topped cake to form sandwiches, then cover with plastic wrap and chill in the fridge for at least 30 minutes or until ready to serve.