Ingredients:

  • 1 cup (240ml) water
  • 1/2 cup (115g) unsalted butter, cut into cubes
  • 1/4 teaspoon (1.5g) salt
  • 1 cup (120g) all-purpose flour, sifted
  • 4 large eggs
  • 2 cups (470ml) whole milk
  • 1/2 cup (100g) granulated sugar
  • 1/4 cup (30g) cornstarch
  • 1/4 teaspoon (1.5g) salt
  • 4 large egg yolks
  • 2 tablespoons (30g) unsalted butter
  • 1 teaspoon (5ml) vanilla extract
  • 6 ounces (170g) semi-sweet chocolate, finely chopped
  • 1/2 cup (120ml) heavy cream
  • 1 tablespoon (15g) unsalted butter

Instructions:

  1. Combine water, butter, and salt in a saucepan. Bring to a boil.
  2. Remove from heat and add flour all at once. Stir vigorously with a wooden spoon until a smooth dough forms and pulls away from the sides of the pan.
  3. Transfer dough to a mixing bowl and let cool slightly.
  4. Gradually add eggs, one at a time, beating well after each addition. The dough should be smooth and glossy, and slowly fall from the spoon in a V shape.
  5. Transfer dough to a piping bag fitted with a large round tip.
  6. Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.
  7. Pipe 4-inch (10cm) logs of dough onto the prepared baking sheet, leaving space between each.
  8. Bake for 15 minutes at 400°F (200°C), then reduce heat to 350°F (175°C) and bake for another 20-25 minutes, or until golden brown and puffed.
  9. Turn off oven and crack open the door slightly. Let éclairs cool completely in the oven to prevent them from collapsing.
  10. Heat milk in a saucepan until almost simmering.
  11. In a separate bowl, whisk together sugar, cornstarch, salt, and egg yolks.
  12. Gradually whisk a small amount of the hot milk into the egg yolk mixture to temper it.
  13. Pour the tempered mixture back into the saucepan with the remaining milk. Cook over medium heat, whisking constantly, until the cream thickens and comes to a boil.
  14. Remove from heat and stir in butter and vanilla extract.
  15. Pour pastry cream into a bowl, cover with plastic wrap (pressing directly onto the surface to prevent a skin from forming), and refrigerate for at least 1 hour.
  16. Place chopped chocolate in a heatproof bowl.
  17. Heat heavy cream in a saucepan until just simmering.
  18. Pour hot cream over the chocolate and let sit for 1 minute.
  19. Stir gently until the chocolate is melted and smooth. Stir in butter.
  20. Once éclairs are cooled and pastry cream is chilled, use a small knife to make two or three small holes in the bottom of each éclair.
  21. Fill a piping bag with pastry cream and pipe the cream into the éclairs until they are full.
  22. Dip the top of each éclair into the chocolate ganache, or spread the ganache over the tops.
  23. Let ganache set before serving.