Fairy cakes with butter...

[Carrotsandcelery]

I usually make my fairy cakes with low fat Flora or low fat Bertolli spread. Today I had some unsalted butter so I thought I would use it up on the fairy cakes.
They are flatter than usual and they taste "cloying" or greasy. I used the same recipe I usually use:
4 oz butter
4 oz sugar
2 eggs
4 oz sr flour
I have never had a problem, ever, with this recipe for fairy cakes before.
Does butter do this?

Not normally in my experience, but I use plain flour and baking powder for cakes and have done for years.