Then I piped the still-soft ganache into the center of each cupcake:
I had extra ganache after all the cakes were filled, so I piped out bite-sized bits of ganache into candy papers to make "naked" truffles. (To make them proper truffles, first warm them up to room temperature and then roll them in a coating--like cocoa powder or finely ground nuts.)
I frosted the cupcakes using a star-shaped pastry tip and lightly sprinkled them with green sanding sugar.
Here's the finished product! The Guinness in the batter wasn't detectable; it just added a certain smoky depth. (It reminded me a lot of my family's traditional chocolate birthday cake, which has a cup of strong coffee in the batter.) The ganache was a rich, dense surprise for the unsuspecting eater. My favorite part was the Bailey's-laced frosting. The addition of the liqueur transported a regular frosting to something heavenly.Note to the bakers out there: These cupcakes do not "dome up" when you bake them, making them perfect for when you want a flat-topped finished product. They'd be the right choice if you were laying a complicated fondant "cap" over your cupcakes, or if you wanted to emulate the look of a Hostess cupcake.