I was responding to your line "* That we Americans think muffins are a kind of tea cake with raisins. I'm not sure what that's all about.*" - because from my perspective American muffins are a weird tea cake.
Other options:
no subject
I was responding to your line "* That we Americans think muffins are a kind of tea cake with raisins. I'm not sure what that's all about.*" - because from my perspective American muffins are a weird tea cake.