My favorite cupcake recipe comes from the March 2005 Cooks' Illustrated. Currently the recipe is available for free on their subscription Web site, but I've also copied it below.
It makes twelve cupcakes and cannot be doubled. The cupcakes come out with a tender, moist crumb and a rich, chocolate taste. I have topped them with coffee flavored frosting, peanut butter frosting, and chocolate frosting. The coffee frosting is great but I doubt children would like it so keep that recipe for adults! I know that I would have been woefully disappointed as a child if I bit into a delicious homemade cupcake only to discover it had coffee frosting!
Dark chocolate cupcakes:
Easy coffee buttercream:
In standing mixer fitted with whisk attachment, beat butter at medium-high speed until smooth, about 20 seconds. Add confectioners' sugar and salt; beat at medium-low speed until most of the sugar is moistened, about 45 seconds. Scrape down bowl and beat at medium speed until mixture is fully combined, about 15 seconds; scrape bowl. Dissolve instant espresso in vanilla and cream, and beat at medium speed until incorporated, about 10 seconds, then increase speed to medium-high and beat until light and fluffy, about 4 minutes, scraping down bowl once or twice. The frosting may be made ahead and refrigerated but bring it to room temperature before using. The recipe may be doubled to make enough for a two layer cake.