Preparation

• Position a rack in the lower third of the oven and heat the oven to 350°F. Line 12 standard-size muffin cups with paper liners.
• Put the unsweetened chocolate in the top of a double boiler or in a metal bowl set over a small saucepan of barely simmering water. Stir occasionally until the chocolate is melted and smooth. Set aside to cool slightly.
• 将面粉，小苏打和盐筛入一个小碗。在一个大碗中，用台式搅拌机以中等速度装有桨叶附件（或手动搅拌机）的架子搅拌机，直到黄油光滑，30到60秒。混合器运行后，慢慢倒入糖。停止搅拌机，刮擦碗和搅拌器，然后以中高速搅拌，直到混合物轻巧蓬松，2至3分钟。每次以中等速度打一个鸡蛋，一次跳动，直到每次添加后面糊（大约30秒）后面糊光滑。每次添加后刮擦碗。加入香草和融化的巧克力（可能会稍微温暖），然后搅拌直至光滑并混合。在低速下，将干成分分为三期，与浓缩咖啡进行两次添加，亚搏手机版官方每次添加后才混合，直到面糊光滑为止。用手搅拌巧克力片。
• Divide the batter evenly among the prepared muffin cups. (Use two rounded soupspoons: one to pick up the batter, one to push it off.) Don’t smooth the batter. Bake until the cupcakes spring back when gently pressed in the center, 20 to 22 min. Let them cool in the tin for 5 min. on a wire rack. Carefully remove the cupcakes from the tin, set them on the rack, and let cool completely.
• Put a generous spoonful of the frosting on top of each cupcake and use the back of the spoon to spread and swirl it. Let the frosting set for about 30 min. before serving.