These cupcakes are almost entirely chocolate, and contain no raising agent, so they are dense and sticky. They crack beautifully on top and I think are yummy enough and pretty enough to serve on their own. I thought the frosting was good, but a bit weird since the cake contains toasted walnuts and the icing has peanut - the two flavours are surprisingly different. M says he likes these ones better than the coke cupcakes based purely on the icing: he doesn't get the salt thing with the peanut butter.
I'm glad I made some of these in miniature size - they're pretty rich, and I wouldn't want to give the kids a big one. But the peanut butter frosting balanced out the sweetness of the brownie so, as an adult, it was easy to eat a whole grown-up sized one. They are tasty without the icing - the gooey centre is yummy, and somehow all the chopped walnuts seem to end up there.
What I liked the most was that when I forgot that a batch was in the oven (only for about 4 extra minutes, but when baking time is only about 15, that's a lot), they weren't over cooked - the nice chewy bit around the edges was a bit thicker, but the centre was still soft and moist.. and the middle bit sunk a bit too, so it could hold a bit more icing - often a winner in my books.
Really, it is just a chocolate brownie baked into a cupcake shape. But you know what? That's OK with me. I'd have them with or without the icing, and it might be my new go-to brownie recipe.
Credit where credit's due: the recipe for the brownie cupcake is from http://www.epicurious.com/, and the frosting as per the coke cupcake post.