Guinness Cupcakes with Whiskey Mascarpone Frosting

Yeah, it's that time of year again. Guinness cupcakes are all over the place. And for good reason: they're tasty. The subtly bitter beer flavor pairs well with chocolate. But unlike the standard Irish Cream or plain cream cheese frosting, I thought I'd go over board this time.
Taking a tip from the Tiramisu cupcakes I make, (which I realize now I haven't actually posted), I opted for a whiskey "curd" that is then mixed with cream cheese and mascarpone to make a soft, rich and flavorful frosting that kicks buttercream's butt any day. Not that there's anything wrong with buttercream, but did you hear me say mascarpone? Can you ever beat that, really? Besides, you can pack in a lot more alcohol flavor in this way. ;-)

So here goes:

Whiskey Curd
Best to make this first as it needs time to cool.

• 2 eggs
• 3/4 cup sugar
• 1/3 cup Whiskey of choice

In a heat proof bowl, whisk together egg and sugar until creamy. Heat over a saucepan of boiling water (don't let the bottom of the bowl touch the boiling water), whisking constantly for about 15-20 minutes (should get a little thick). Pour in whiskey and whisk until mixture is thick like pudding). Remove from heat (be careful of the steam) and pour into a cool dish. I just let mine sit out until I was ready to make the frosting, but you could cover closely with saran wrap and let cool in the fridge. It keeps for a couple days too, if you want to make it ahead.

Guinness Cupcakes 
(I stole this recipe a while ago so am not even sure where from any more. Sorry blogosphere!)
Makes Approx. 12-15 cupcakes

• 1/2 cup Guinness
• 1/4 cup butter, sliced
• 1/4 cup cocoa
• 1 cups superfine sugar
• 1/3 cup sour cream
• 1 eggs
• 1/2 tablespoon vanilla extract
• 1 cups all-purpose flour
• 1 + teaspoons baking soda

Preheat over to 350˚. Line cupcake tins.
Heat Guinness and butter in a saucepan until butter has melted. Whisk in cocoa and then sugar. In a separate bowl, mix sour cream, egg, and vanilla. In a bigger bowl whisk together flour and baking soda. Gradually pour the Guinness mixture into flour bowl until just incorporated, then add sour cream mixture. (This is totally backwards from how the instructions were written, but it seemed to work fine).
Fill cupcake liners 3/4 way full (exactly 1/4 cup measure will do, btw, which is my preferred method for filling tins).
Bake for 20 minutes. Cool.

Whiskey Mascarpone Frosting
Once curd and cupcakes have cooled, make frosting. This will make more frosting than you have cupcakes for, but not quite twice as much (if you were to double the cupcake recipe).

• 4 oz. cream cheese
• 4 oz. mascarpone
• Whiskey curd 
• 1/2 cup sifted powdered sugar

Whip cream cheese and mascarpone together until smooth. Scrape sides of bowl, then add in curd gradually, making sure to scrape the sides of the bowl as you go. Once incorporated and fluffy, add in the powdered sugar, and whip until the mixture has firmed up slightly. It's going to be a pretty soft frosting, so don't try anything too fancy as far as decorating or piping. A dollop on top of the cupcake works nicely for me. You can add a more firm buttercream frosting on top if you want to get fancy with the St. Patty's Day pride.

Don't eat cupcakes and drive!
Just kidding, they're not that strong. But do enjoy!