Boston Cream Pie

Ingredients

• 2 tablespoons unsalted butter plus more for pan
• 1 1/4 cups sugar plus more for pan
• 1 1/4 cups sifted cake flour (not self-rising)
• 1 1/4 teaspoons baking powder
• 3/4 teaspoon salt
• 2 large eggs
• 2 large egg yolks
• 3/4 cup whole milk
• 2 teaspoons pure vanilla extract
• 7 tablespoons heavy cream
• 3 ounces best-quality semisweet chocolate coarsely chopped
• 2 cups milk
• 1/2 cup sugar
• 4 large egg yolks
• 2 teaspoons pure vanilla extract
• 1 salt
• 6 tablespoons cornstarch

Instructions

1. 1
   Preheat oven to 350 degrees. Make the cake: Lightly butter a 9-by-2-inch round cake pan, and line with parchment paper. Butter parchment, and sprinkle with sugar, tapping out excess; set aside.
2. 2
   In a medium bowl, whisk together flour, baking powder, and salt; set aside. In the bowl of an electric mixer fitted with the whisk attachment, whisk eggs and egg yolks on medium speed for 1 minute. Gradually add sugar, and continue beating until light and fluffy, about 3 minutes.
3. 3
   Meanwhile, heat milk and butter until hot in a small saucepan over medium heat; being careful not to boil the milk. Remove from heat, and stir in vanilla. With mixer still running, slowly add hot milk to egg mixture. Gradually add flour mixture, 1/4 cup at a time, mixing until incorporated. Transfer to prepared pan.
4. 4
   Bake until cake is golden brown and a tester inserted into the center comes out clean, 35 to 40 minutes. Transfer to a wire rack, and cool for 15 minutes. Remove from pan, leaving the cake bottom-side up. Let cool completely.
5. 5
   Make the glaze: In a small saucepan over medium heat, bring heavy cream to a boil. Place chocolate in a medium bowl, and pour cream over chocolate, stirring until chocolate is melted and well combined. Set aside to cool slightly, about 10 minutes.
6. 6
   To assemble cake: Remove pastry cream from refrigerator. Beat with a stiff whisk until cream is smooth. Split cake in two even layers; spread bottom half with the pastry cream filling. Top with remaining layer. Pour glaze over center of cake, allowing it to spread, covering top and dripping down the sides. Chill cake for 20 minutes before serving.
7. 7
   Pastry Cream Filling: In a medium saucepan, combine milk and 1/4 cup sugar over medium heat, and bring to a simmer. Meanwhile, in a medium bowl, whisk egg yolks and remaining 1/4 cup sugar until well combined. Whisk in vanilla and salt. Whisk in cornstarch, 1 tablespoon at a time, until fully incorporated. While whisking egg mixture constantly, slowly add 1 cup of the heated milk to the egg mixture. Strain this mixture into milk remaining in saucepan. Continue cooking over medium heat, whisking constantly, until mixture comes to a full boil, 4 to 6 minutes.
8. 8
   Transfer to a medium bowl, and cover with plastic wrap, pressing wrap against the filling to prevent a skin from forming. Refrigerate until at least 3 hours and up to overnight.