3tablespoonscoconut oil, shortening or a neutral oil (see notes)
Instructions
Make the Cupcakes. Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners, then line a second tin with 6 liners (this recipe makes about 18 cupcakes).
Melt the chopped chocolate in a heatproof bowl set over simmering water or in the microwave at 50% power, stirring every 30–40 seconds. Let cool slightly.
In a medium bowl, whisk together flour, salt, baking soda, and cocoa powder. Set aside.
In a stand mixer fitted with the paddle attachment, beat butter and sugar on low speed until blended. Add eggs and yolks one at a time, mixing after each addition.
Add the melted chocolate and mix until blended. Beat in oil and vanilla, then mix in sour cream.
Add dry ingredients and coffee (or water) alternately in three additions, mixing on the lowest speed just until blended.
Fill cupcake liners about ⅔ full and bake for 18–20 minutes, until the tops spring back lightly.
Remove cupcakes from the pan and cool completely.
Beat just until smooth and spreadable. Chill frosting 10–15 minutes if needed before piping.
Vanilla Bean Buttercream
Make the Vanilla Bean Buttercream. Beat butter until smooth and creamy, about 2–3 minutes.
Gradually beat in powdered sugar, followed by milk, vanilla, and salt.
Pipe tall swirls of frosting onto cooled cupcakes. Refrigerate cupcakes for 20–30 minutes to firm the frosting.
Melt chocolate with oil until smooth, then let cool slightly.
Dip cupcakes quickly into the chocolate, letting excess drip off. Set on a rack or parchment-lined tray until the coating firms. Note: If dipping doesn't work for you, you can try holding the cupcake in one hand and just drizzling the chocolate mixture over with a spoon, turning to coat.
Notes
For a slightly firmer, whiter frosting, you can replace ¼ to ⅓ of the butter in the frosting with vegetable shortening such as SpectrumYou can use any chocolate for the shell. I liked the Ghirardelli bittersweet, but I've also tested these with just a mix of chocolate that I had in the pantry combined with some coconut oil.Chill cupcakes before dipping for the cleanest chocolate shell.These cupcakes are best served the day they’re made but can be refrigerated overnight.