Chocolate-Frosted Éclairs

Ingredients

• 1 cup water
• 1 stick (4 ounces) unsalted butter
• 2 tablespoons sugar
• 1/4 teaspoon salt
• 1 cup plus 2 tablespoons all-purpose flour
• 4 large eggs
• 2 cups whole milk
• 1/4 vanilla bean, seeds scraped
• 1/2 cup plus 2 tablespoons sugar
• 5 tablespoons cake flour
• Pinch of salt
• 1 large egg
• 2 large egg yolks
• 1/4 cup plus 2 tablespoons heavy cream
• 4 ounces bittersweet chocolate
• 4 tablespoons unsalted butter, softened

Steps

1. Make the choux pastry Preheat oven to 400°F. In a medium saucepan, bring water, butter, sugar, and salt to a boil over moderate heat. Add flour and stir vigorously with a wooden spoon for about 2 minutes, until dough comes together and a film forms on the bottom of the pan. Remove pan from heat. Transfer dough to a large bowl and beat at medium speed until just slightly cooled, about 1 minute. Add eggs, 1 at a time, beating well after each addition.
2. Transfer dough to a pastry bag fitted with a 1-inch round tip. Pipe 12 (5-inch-long) logs onto a parchment-lined baking sheet. Bake for 10 minutes. Turn oven down to 325°F and bake shells for 30 minutes longer, until golden brown. Transfer to a rack and let cool.
3. Make the pastry cream In a medium saucepan, bring milk, vanilla bean, and seeds just to a boil. Meanwhile, in a large bowl, whisk sugar with cake flour and salt. Whisk in egg and egg yolks. Slowly add hot milk, whisking constantly. Pour mixture back into saucepan and bring to a boil over moderate heat, whisking constantly. Continue to boil pastry cream, whisking constantly, until thick, about 30 seconds longer. Immediately strain pastry cream through a fine sieve into a medium bowl. Cover with plastic wrap and refrigerate for at least 30 minutes, or until cool.
4. In a medium bowl, whip heavy cream until soft peaks form. Whisk pastry cream, then fold in whipped cream until blended.
5. Make the chocolate glaze In a medium bowl, melt chocolate in the microwave at 50% power, being careful not to overheat it. Whisk in butter until smooth.
6. Assemble the chocolate éclairs With a serrated knife, split éclair shells lengthwise. Spoon a generous amount of the pastry cream into the bottom half of each shell. Dip top half of each shell into the chocolate glaze, close éclairs, and serve.