INSTRUCTIONS
Make the pastry cream: Heat the heavy cream in a medium saucepan over medium heat until it simmers, stirring occasionally. Meanwhile, beat the egg yolks, sugar and salt in a medium bowl. Add cornstarch and whisk until mixture is pale yellow and thick, about 15 seconds.
When the cream reaches a boiling point, slowly beat in the yolk mixture. Return the mixture to the pan and cook over medium heat, stirring constantly, until it has the consistency of a thick pudding, 1 to 2 minutes. Remove pan from heat and whisk in butter and vanilla extract until butter is completely melted. Transfer the pastry cream to a small bowl and press the plastic wrap directly onto the surface. Refrigerate until ready, at least 2 hours or up to 2 days.
Make the pastries: Preheat oven to 350 degrees F. Line a standard 12-cup muffin tin with paper liners and set aside. In the bowl of a stand mixer, with the paddle attachment, combine the flour, sugar, baking powder and salt at medium-low speed. Add the butter and mix until the mixture looks like coarse sand. Add the eggs, mixing gently until incorporated. Add milk and vanilla extract; to avoid splashing, mix at low speed and then increase to medium speed, mixing until light and fluffy and no lumps remain, about 3 minutes, stopping to scrape sides and bottom of bowl halfway through. The dough will be almost “frothy” to the touch.
Fill cups with muffins three-quarters full and bake until a toothpick inserted in the center of a muffin comes out clean, 19-20 minutes. Let the cupcakes cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.
Make the icing: Combine the heavy cream, corn syrup, chocolate and vanilla in a small saucepan over medium heat, stirring constantly, until smooth. Set aside to cool and thicken at room temperature for at least 1 hour (I leave mine longer to thicken to a frosted consistency. Cool it in the refrigerator a bit, if necessary).
Assemble the cupcakes: Using a kitchen knife, cut into the center of the cupcake at a 45-degree angle about ⅛-inches from the edge and cut along the length. Remove the cone and cut all but the top ¼-inch, leaving a small cake disk.
Fill the inside of each muffin with room temperature pastry cream and place the pie disc on top. Spread the chocolate icing over each muffin, covering the top completely. Refrigerate the muffins until the icing is ready, about 10 minutes. Serve at room temperature.