Making Whoopie!

Pies!* I've been slightly obsessed with Whoopie Pies for the last year. I finally made a batch. I used a Williams Sonoma recipe for the pie and this recipe for the filling. Overall they were good, but I want a better filling recipe. Any tips? I think that the powder sugar taste is too strong. Also, as you can see in the picture the filling was a little oozy.


*apologies for lamest title maybe ever.