Some cupcakes have bottoms that look fine, like the one on the right side. But most of them are deformed, which is bad because i sell my cupcakes. What do you think may be causing this shape? Could it be the foil liner that I use? The inside of it is paper but it can't be separated from the foil. I choose foil over paper liners because they hold moist cupcakes better.
This is how the top of the cupcakes look like:
The cupcakes did rise but leave hollow bottoms.
Thank you so much in advance