Preparation Method
- Preheat the oven to 375°F (190°C) with a rack set in the middle position. Line a cookie sheet with parchment paper.
- Make the pâte à choux: In a medium saucepan over high heat, bring 1 cup (240 milliliters) water, butter, granulated sugar, and salt to a rapid boil. Lower the heat to medium-low and add flour all at once. Using a wooden spoon, stir vigorously until the dough comes together and is smooth, 2–3 minutes. The dough is ready when it pulls away from the sides of the pan to form a ball, the surface looks shiny and glossy, and it’s thick enough for a spoon to stand upright in the middle. (A thin film on the bottom of the pan is normal.) Remove the pan from the heat.
- In the mixing bowl of the stand mixer fitted with the flat beater attachment, add the dough and beat on medium (5–6) speed for 1 minute to cool. Reduce the speed to medium-low (3–4), and add eggs one at a time, incorporating each before the next addition, about 4 minutes.
- Using a pastry bag fitted with a large (size 1A) round tip, pipe the dough into 1-by-4-inch (3-by-10-centimeter) lines about 2 inches (5 centimeters) apart on the prepared baking sheet.
- Bake until dark golden brown, 25–30 minutes. Turn off the oven and leave the cookie sheet of éclair shells in the oven for 10 minutes to release the remaining moisture. (Do not open the oven.) Remove and let cool for 10 minutes.
- Make the crème pâtissière: In a small bowl, combine egg yolks, granulated sugar, flour, cornstarch, and salt. Set aside. In a medium saucepan over medium heat, cook milk and vanilla bean seeds until the mixture begins to foam. Slowly pour half of the hot milk mixture into the egg mixture and whisk vigorously until blended. Pour the egg and milk mixture back into the remaining half of the hot milk mixture. Whisking constantly, bring the mixture to a simmer and cook until thickened. Pour the mixture into a small bowl and press plastic wrap onto the surface of the mixture.
- Make the chocolate glaze: In a small saucepan over medium heat, add heavy cream and chocolate. Heat until the chocolate is melted. Remove pan from the heat and stir in butter, one tablespoon at a time, until blended. Add corn syrup and stir until blended.
- To assemble, use a skewer to make a hole in each end of the éclair shells. Using a pastry bag fitted with a filling tip (size 230), pipe the crème pâtissière into one end of the shells. Then fill the opposite end until the crème starts to push out of the first end. Place the filled shells on a wire rack with parchment paper underneath. Spoon the chocolate glaze over the top of each shell. Let stand until the chocolate has set. Chill until ready to serve.
Pro Tip
For uniform éclairs, create a guide by using a ruler to draw evenly spaced 4-inch-long (10-centimeter-long) lines on a piece of parchment. Place another piece of parchment on top of the marked one and pipe along the lines. For the second sheet pan, simply slide the marked parchment out from underneath and flip it over to line the second sheet pan before piping.
