Ingredients:

  • 1 cup Water
  • 1/2 cup (113g) Unsalted Butter, cut into cubes
  • 1 tablespoon Granulated Sugar
  • 1/2 teaspoon Salt
  • 1 cup (120g) All-Purpose Flour, sifted
  • 4 Large Eggs, room temperature
  • 2 cups Whole Milk
  • 1/2 cup (100g) Granulated Sugar
  • 1/4 cup (30g) Cornstarch
  • 4 Large Egg Yolks
  • 2 tablespoons (28g) Unsalted Butter, cubed
  • 1 teaspoon Vanilla Extract
  • Pinch of Salt
  • 6 oz (170g) Dark Chocolate (60-70% cocoa solids), finely chopped
  • 1/2 cup (120 ml) Heavy Cream
  • 1 teaspoon Light Corn Syrup (Optional)

Instructions:

  1. Preheat oven to 400°F (200°C). Grease and line a 9x13 inch dish with parchment paper, ensuring an overhang.
  2. Bring water, butter, sugar, and salt to a rolling boil in a saucepan. Remove from heat immediately.
  3. Dump in all the sifted flour at once. Stir vigorously until a smooth dough ball forms and pulls away cleanly from the sides (the panade stage).
  4. Return pan to low heat and cook, stirring constantly, for 1-2 minutes to dry out the dough. Transfer dough to a mixing bowl and beat for 1 minute to cool slightly.
  5. Add eggs one at a time, beating well after each addition until fully incorporated, resulting in a smooth, glossy dough. Spread the batter evenly into the prepared dish.
  6. Bake for 20-25 minutes until puffed, golden brown, and firm. Do not open the oven door early. Remove from oven, prick the surface to release steam, and let cool completely.
  7. For the pastry cream: Gently warm the milk and vanilla in a saucepan until steaming. In a separate bowl, whisk together sugar, cornstarch, salt, and egg yolks until pale.
  8. Temper the yolks by slowly pouring about half of the hot milk into the yolk mixture while whisking constantly. Pour the tempered mixture back into the saucepan with the remaining milk.
  9. Cook over medium heat, whisking vigorously and constantly, until the mixture thickens dramatically and boils for 1 minute. Remove from heat, whisk in the cubed butter until smooth. Pour into a shallow dish, cover the surface directly with plastic wrap, and chill completely (at least 1 hour).
  10. Once the choux base is cool, use a fork to gently score and rough up the top surface. Beat the chilled pastry cream briefly to smooth it out, then spread it evenly over the cooled choux base.
  11. Chill the cake for at least 1 hour to allow the cream to set firmly.
  12. Prepare the glaze: Heat the heavy cream until just simmering. Pour over the chopped chocolate and let sit for 2 minutes, then gently whisk until smooth. Stir in corn syrup, if using.
  13. Pour the warm glaze evenly over the chilled cream layer. Refrigerate for at least 2 hours before slicing cleanly with a hot, sharp knife.