When I was making Pecan tassies, I read the recipe wrong and put a stick of butter in for the filling instead of 2 tablespoons. There are two eggs, 1 1/2 cups brown sugar, vanilla extract. Will it turn out with that much butter?
I'm assuming your stick of butter is 8 tablespoons, right? So you used four times as much butter as the recipe calls for, which is probably enough to make it into a buttery mess.
I think your two best options are: 1) increase all other ingredients by the same amount and make a lot of tassies, or 2) start over.