Chocolate Eclairs

In a medium saucepan, combine the milk and vanilla bean. Bring to a boil over medium heat, then immediately turn off the heat and set aside to infuse for 15 minutes. Remove the vanilla bean pod.

In a bowl, whisk the egg yolks and sugar until light and fluffy, about 1 minute. Add the cornstarch and whisk vigorously until no lumps remain. Whisk in ¼ cup of the hot milk mixture until incorporated. Whisk in the remaining hot milk mixture, reserving the saucepan. Pour the mixture through a fine mesh strainer back into the saucepan.

Cook over medium-high heat, gently whisking constantly, until thickened and slowly boiling, 3 to 5 minutes. Remove from the heat and stir in the butter until fully melted and combined. Transfer to a clean bowl and press plastic wrap directly onto the surface of the pastry cream to prevent a skin from forming. Let cool slightly at room temperature, then chill for at least 2 hours or until ready to serve. The custard can be made up to 24 hours in advance.

Preheat the oven to 425°F. Using a pencil, draw ten 4-inch-long lines on one side of a sheet of parchment paper, spacing them a few inches apart. Flip the paper over and place it on a large baking sheet. Fit a large pastry bag with a large round tip. Set both aside.

In a large saucepan, combine the water, butter, sugar, and salt, and bring to a rolling boil over medium-high heat, about 5 minutes.

When it is boiling, immediately take the pan off the heat. Stirring with a wooden spoon, add all the flour at once, and stir hard until all the flour is incorporated, 30 to 60 seconds.

Return the pan to medium heat and stir constantly for 30 seconds. Scrape the mixture into the bowl of a mixer fitted with a paddle attachment (or use a hand mixer).

Start mixing at medium speed. With the mixer running, add 3 eggs, one at a time, stopping to scrape down the sides of the bowl after each addition. Mix until the dough is smooth and glossy and the eggs are completely incorporated. The dough should be thick but should fall slowly and steadily from the paddle when you lift it out of the bowl. If the dough is still clinging to the paddle, beat the remaining egg, then mix in a little bit at a time until the dough is thick but will ribbon off of the paddle.

Carefully transfer the choux dough to the pastry bag. Pipe fat lines of dough 4 inches long (about the size and shape of a jumbo hot dog) onto the parchment paper-lined baking sheet, leaving 2 inches of space between each. You should have 8 to 10 lines of dough.

Use your fingers dipped in cool water to smooth out any bumps or points of dough. Bake for 15 minutes. Reduce the heat to 375°F and continue baking until puffed and light golden brown, about 25 minutes more. Try not to open the oven door too often during the baking. Once golden, remove from the oven and immediately poke two holes in the bottom using a skewer to release steam. Let the pastry shells cool completely on a wire rack.

Poke a hole in the end of each cooled eclair shell, or two larger holes on the bottom, using a small pastry tip.

Remove the pastry cream from the fridge and whisk it vigorously until smooth and loosened up. Transfer it to a pastry bag fitted with a medium plain piping tip. Gently pipe the custard into the eclairs through the holes, filling them until just full. Place them back on the wire rack once filled.

Heat the cream in a small saucepan over medium heat or by microwave in a medium bowl, just until it starts to bubble and steam. Add the chocolate, and let stand for 2 minutes on the counter. Gently whisk until melted and smooth.

Dip the tops of the eclairs in the warm chocolate glaze and set them on a small pan or plate. Chill, uncovered, for at least 1 hour to set the glaze, or keep refrigerated until ready to serve. Eclairs should be stored in an airtight container in the fridge for up to 2 days.