• Adjust your oven rack to where it's in the middle position. Preheat your oven to 350°F. Fit a 12-cup muffin pan with the liners and set aside.
• Fill a medium saucepan with about 2 inches of tap water. Over medium heat, bring to a hot simmer. Rest a medium mixing bowl comfortably inside the saucepan. The bottom of the bowl should be above the water but NOT touching the water.
• To the medium bowl, add butter, bittersweet chocolate, and Dutch process cocoa. Heat until the butter and chocolates are melted, whisking briskly, and very well combined. Once silky and smooth, set the chocolate mixture aside to cool.
• In a large mixing bowl, whisk together flour, baking soda, and baking powder. In a separate bowl, whisk together the eggs with the granulated sugar and salt. This mixture should be very light, lofty, and fluffy. Add the cooled chocolate to the egg mixture, stirring, then some sour cream. Stir again until this is well combined.
• Sifting in one third of the flour mixture at a time, whisk briskly ensuring the batter is smooth after each addition. Divide the batter evenly into your prepared cupcake pan. Bake for 18-20 minutes, then remove from the oven. Pop the cupcakes out and onto a wire rack to cool completely before frosting.

basic cream cheese frosting

• Beat cream cheese and butter with an electric mixer on medium-low speed until smooth. Gradually add powdered sugar, beating at low speed until blended after each addition. Stir in vanilla. Increase speed to medium-high, and beat until fluffy, 1 to 2 minutes. Refrigerate 10 minutes to stiffen before frosting with offset spatula or load immediately into a piping bag without refrigeration.