I made this recipe last night and it turned out perfectly. Regarding the comment below, I whipped the melted butter with the sugar for about 5 min until it got thick and pale yellow.
I tried this recipe and it didn't turn out at all. I'm an experienced cupcake baker so I think the problem is with the melted butter. If I try it again, I will used room temp butter instead. Mine sunk in the middle and overflowed the pan around the edges. Very strange. They tasted good however and we filled the holes with the whipped cream but still I was so disappointed after spending the time and effort.