Ingredients:

  • 1 ¾ cups All-Purpose Flour (sifted)
  • 1 ¾ cups Granulated Sugar
  • ¾ cup Unsweetened Cocoa Powder (Dutch-processed preferred)
  • 1 ½ tsp Baking Soda
  • 1 tsp Baking Powder
  • 1 tsp Fine Sea Salt
  • 2 Large Eggs (room temperature)
  • 1 cup Buttermilk (room temperature)
  • ½ cup Vegetable Oil
  • 2 tsp Vanilla Extract
  • 1 cup Hot Brewed Coffee
  • 2 cups Whole Milk
  • ½ cup Granulated Sugar (for filling)
  • 4 Egg Yolks
  • ¼ cup Cornstarch (Cornflour)
  • 2 Tbsp Unsalted Butter (cubed)
  • 1 tsp Vanilla Bean Paste
  • 6 oz Semi-sweet Chocolate (chopped, for optional frosting)
  • ¾ cup Heavy Cream (for optional frosting)

Instructions:

  1. Phase 1: Making the Cream Filling. Gently heat 2 cups of whole milk and vanilla bean paste in a saucepan until simmering. Remove from heat.
  2. In a separate bowl, vigorously whisk the 4 egg yolks, ½ cup of sugar, and cornstarch until pale and smooth (ribbon stage).
  3. Temper the yolks by slowly pouring half of the hot milk into the yolk mixture while whisking constantly.
  4. Return the tempered mixture to the saucepan with the remaining milk. Cook over medium heat, whisking continuously, until the mixture thickens significantly and bubbles slowly (about 1-2 minutes after boiling starts).
  5. Remove from heat. Whisk in the 2 Tbsp of cold cubed butter until melted and smooth. Strain the pastry cream through a fine-mesh sieve into a clean bowl. Cover the surface directly with plastic wrap and chill for at least 1 hour until cold and firm.
  6. Phase 2: Baking the Cupcakes. Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners.
  7. In a large bowl, whisk together the flour, 1 ¾ cups sugar, cocoa powder, baking soda, baking powder, and salt (dry ingredients).
  8. In a separate bowl, combine the eggs, buttermilk, vegetable oil, and 2 tsp vanilla extract (wet ingredients).
  9. Pour the wet ingredients into the dry ingredients and mix on low speed until just combined. Slowly stream in the 1 cup of hot coffee until the batter is smooth and very thin.
  10. Divide the batter evenly into the liners (two-thirds full). Bake for 20–22 minutes, or until a toothpick comes out with moist crumbs attached.
  11. Cool the cakes in the tin for 5 minutes, then transfer them to a wire rack to cool completely.
  12. Phase 3: Assembly. Transfer the chilled pastry cream to a piping bag fitted with a narrow filling tip.
  13. Using a corer or small knife, gently remove a cone-shaped plug from the centre of each cooled cupcake, leaving the base intact.
  14. Pipe the chilled cream generously into the cavity until the top is slightly mounded. If using optional frosting, top the filled cupcakes as desired.