1. Preheat oven to 350 degrees F. Place paper baking cups into every other cup of a cupcake tin. Spray baking cups with nonstick cooking spray and fill each remaining cup with 1/4 cup water.
2. In a medium bowl, using a whisk, combine cake flour with 1/4 cup of the sugar.
3. In a large bowl, mix 3/4 cup of the sugar and egg yolks at high speed until thick and very pale, about 3 minutes, scraping down sides often. Add espresso, vanilla extract, and salt to mixture and beat at low speed until blended. Add flour mixture and beat, scraping down sides, until blended.
4. In a separate bowl with very clean beaters, beat egg whites at high speed until soft peaks appear. Gradually add remaining 1/4 cup sugar, and continue beating until stiff peaks form.
5. Fold a quarter of egg white mixture into egg yolk batter to lighten it; then fold in remaining whites.
6. Use a measuring cup to ladle batter into baking cups, filling each just over 3/4 full. Bake about 14 to 16 minutes, until light golden brown on top. Tops should bounce back and feel dry when you touch them. Cool cupcakes on wire rack. Repeat with remaining batter.
7. While cupcakes cool, prepare topping. In a microwaveable dish, combine milk and dark chocolate. Heat on high for about 30 seconds, then stir until chocolate melts and mixture is smooth.
8. Dip tops of cupcakes into chocolate, spreading topping thinly with a spatula if necessary. Let stand about 15 minutes before serving.
Source: Hannaford fresh Magazine, January - February 2007