I have a few problems so I thought I would just make 1 post about everything in hopes someone can help.

1- I usually ice my cakes and put them in my fridge for awhile. The past few cakes have gotten VERY sweaty once I take them out of the fridge for good. No idea why.

2- I made some some butterflies for the cake out of gum paste and fondant and used extra tylose powder b/c they weren't getting as hard as I like. They were stiff, but you could still move them. I want them to where they will hold there shape and not move. What else can I try?

3- I made some buttons out of the same mixture and put it on the cake before putting it in the fridge. Once I took it out, they were super gummy. I've never put fondant in the fridge on a cake so I didn't know.

4- Lately when I've baked cakes the 8-12 inch pans, the cake sticks to the middle of the bottom of the pan. I have to scrape it out and put it back into the cake. The 6 inch pan does not do this. these are new pans. I use crisco on the pan and then flower, just like I've always done. I usually cook on 325. Should I bump the temp up?

I am using a new oven. We just recently moved, that might have something to do with it.

But any ideas are welcomed and appreciated!! Thank you!

I'm not sure how much help I can be but...

2. Have you tried using all gum paste? It dries faster and harder than fondant.
3. What did you use to attach the buttons? It can get gummy when too wet so that could be part of the problem.... Also, if this was on the cake that is sweating, that's a problem too!
4. Have you tried lining your pans? You can line with parchment paper or even wax paper. I line the bottom of all my cake pans with wax paper and spray the sides with non stick cooking spray.

Caking gets more difficult when it's hot/humid (at least for me).

double post

Think about a glass of ice water... the cool glass attracts moisture in the air causing water to form on the outside of the glass. The amount of water that collects is in direct relation to how humid it is. So, is it really humid where you live? Try boxing your cake then wrap in plastic when you put it in the fridge, I've heard this helps with humidity, the moisture is mostly blocked by the plastic and any that gets thru is absorbed by the box. You have to leave it in the box when yo take it out. Could also be your fridge, some have humidity pumped in them which could explain why your fondant is mooshy too.

You don't need to refrigerate your buttercream unless you want to. Your recipe is shelf stable so if you want to leave it out, you should not have any problems.

Line your pans with parchment and get an oven thermometer, especially if it's a new oven to you.

Hope this helps!

Buttercream with milk in it is fine to leave out if the fridge. The sugar preserves it. As far as the crusting, fondant/gumpaste not drying, and the condensation issues, it sounds like it is very humid where you are at the moment.

I would leave the cake out and see if it crusts after being out longer. If that doesn't work I would try reducing the butter down a little bit or add more powder sugar.

Did you have your cake in a cake carrier? If so that will cause fondant pieces on it to get soft and melty. If not, the condensation would cause those problems as well.