Chocolate cupcakes w/Chocolate Buttercream Frosting

I searched far and wide, and suffered a number of disappointments, before I found a chocolate cupcake and frosting recipe that would satisfy me. It is done. I can rest now.

Please enjoy.

Chocolate Cupcakes

Ingredients
12 tablespoons (1 1/2 sticks) unsalted butter, at room temperature
2/3 cup granulated sugar
2/3 cup light brown sugar, packed
2 extra-large eggs, at room temperature
2 teaspoons pure vanilla extract
1 cup buttermilk, shaken, at room temperature
1/2 cup sour cream, at room temperature
1 3/4 cups all-purpose flour
1 cup dutch-processed powder
1 1/2 teaspoons baking soda
1/2 teaspoon kosher salt

Method
Preheat the oven to 350 degrees F. Line cupcake pans with paper liners.
In the bowl of an electric mixer fitted with a paddle attachment, cream the butter and 2 sugars on high speed until light and fluffy, approximately 5 minutes. Lower the speed to medium, add the eggs 1 at a time, then add the vanilla and mix well. In a separate bowl, whisk together the buttermilk, and sour cream. In another bowl, sift together the flour, cocoa, baking soda, and salt. On low speed, add the buttermilk mixture and the flour mixture alternately in thirds to the mixer bowl, beginning with the buttermilk mixture and ending with the flour mixture. Mix only until blended. Fold the batter with a rubber spatula to be sure it's completely blended.
Divide the batter among the cupcake pans (1 rounded standard ice cream scoop per cup is the right amount). Bake in the middle of the oven for 20 to 25 minutes, until a toothpick comes out clean. Cool for 10 minutes, remove from the pans, and allow to cool completely before frosting.


Chocolate Buttercream Frosting

Ingredients
2 1/2 sticks unsalted butter, softened
1 cup confectioners' sugar
3/4 cup Dutch-processed cocoa
Pinch of fine sea salt
3/4 cup light corn syrup
1 teaspoon vanilla extract
8 ounces semisweet chocolate, melted and cooled slightly


Method
In a food processor, process the butter, sugar, cocoa, and salt until smooth, about 30 seconds, scraping the sides of the bowl as needed. Add the corn syrup and vanilla and process until just combined, 5 to 10 seconds. Scrape the sides of the bowl, and then add the melted chocolate and pulse until smooth and creamy, 10 to 15 seconds.