Why did my cupcakes sink while cooling?
I made both the chocolate and the vanilla recipes 5 days apart. Both did not look done at 22 minutes (the max time) so I baked a minute or two longer. Both looked beautiful coming out of the oven and both sank horribly as they cooled. My baking powder is new and fresh. My oven usually bakes according to the time recommended. Any ideas about what went wrong?