Wow – Thanks for the compliments – it’s my first posting!
For the Mouse Hat, I like to use half of my ball pan with extra batter so it makes the sides high enough. It takes longer to cook, but then I don’t have to deal with a layer cake. For a small one, I just use Rice Krispie treats pressed into a rounded shape. (a coffee mug or ice cream scoop can help)
As for tips on the ears, I always cut a thin cardboard circle with a flat Popsicle stick attached/taped to it(be sure to shorten the stick so that it doesn’t go through the bottom or the side). Then I cover it with a thin layer of black fondant – if you make the fondant too thick the weight of it can tear the hat (obviously, I have experience in this occurring…nothing like having a mouse with floppy ears ;-) If you’re making small mouse ears then pre-cut the circle with a corner cut before you press it into the ball hat, since the two ears will sometimes hit each other on the way in.
Allow the “ear-sicles” to dry at least overnight so you won’t have fondant ‘bunching’ at the entry point.
Hope this helps!