The frosting bubbles on my cakes after it sets......does anyone know why?

NOBODY? I do freeze my cakes for about a day but do let them totally defrost first??? I don't understand...its like it pulls away from the cake in some places...crazy....I just stick a toothpick in it and then push it back on to the cake.

it sounds like you need to let your cakes thaw a little more. I freeze my cakes but i let them thaw for about 30-40 minutes before handling them.

As the cake thaws the air expands and if it doesn't have anywhere to go it's going to push out your icing and make it bubble. I've had it happen before when i didn't wait long enough.
Now i did work in a bakery where we used to frost frozen cakes and what we did to prevent bubbling was to poke holes in the cake with scissors or the nail part of the flower nail. in theory it gives the cake somewhere to go... i never had issues when i did it, but thinking back it just doesnt' make sense to me.

I read your original post, and assumed you meant buttercream when you say 'frosting'. Is that what you meant, or did you mean fondant?

Yes the frosting is buttercream. Thank you Leily! I thought that may have something to do with it. The cakes are still cool when I frost them but I thought if I pressed in the center of them and they were not still hard but soft they were defrosted. I guess I really need to let them come to room temperature?

I think you will find the jury out on the frost it frozen/frost it thawed debate. I frost my cakes partially frozen. I let the warm up enough to get a straight torte on them and then ice them while they are still cool and firm. I have a difficult time handling room temperature cake, but that's just me personally.

I am following the techniques I learned in a bakery many years ago. I've only seen bubbles in my buttercream one time and I asked my niece who is a pastry chef why it could happen. She said that perhaps my butter was too cold. If your butter is too cold, and you mix it into the buttercream, you will get little bits of solid butter in the buttercream. When the solid bits of butter come to room temperature they sweat causing moisture in the buttercream which in turn creates bubbles.

Now I'm not a physicist, and I'm sure other reasons will pop up and I certainly don't want to take away from the poster above.
It's just another possible reason this could be happening.

I plan ahead now, and leave my butter sit out for many hours and even over night if I can think that much ahead.

hope this helps,
tokazodo