So I finally ended my very first decorated cake, you will see the pics in my photos, and I'd like to discuss with you all the problems I had to face while making it, hoping I won't have to face them again!!!! 
1- I made the cake with a brownies recipe, actually I made 2 of them. When they first came out of the oven they were perfect, no domes or anything, after a while they "deflated" and had this "hole" in the center of cake...Why?????
2- Filling for this cake was a creamcheese frosting. I followed the recipe carefully, but ended up with a very liquid mass and had to add tons of confectioners sugar. Recipe said I had to mix cream cheese and butter, then had to add the sugar. I used kitchen aid, can it be due to overmixing?
3- I made fondant from scratch the day before decorating. I did not know that I had NOT to put it in the fridge, so when I took it out it was quite sticky and had to add sugar to this too. How to recover a fondant that has been put in the fridge?
4- when cutting the decorations, all edges became sort of rough with small breaks, I tried to smooth them with my finger lightly dipped into water. How to obtain perfect crisp edges when cutting forms?
I hope you may answer my questions, and I hope I won't have to face these problems again, I really got so anxious about it, but I know cake making will eventually become fun......
I'm certainly no expert, but here are some thoughts...
1. Cake pan was too full? Didn't bake in the middle? Or with brownie recipe, there was a bubble in that area, popped when cooled. I would stick to cake recipes in the future.
2. Did the recipe call for adding milk? If so, it sounds like there was too much added. Or recipe called for too much butter/cream cheese, not enough powdered sugar. (I use a recipe I found on Martha Stewart, goes with a guest Martha's red velvet cake)
I don't have answers for 3-4, I don't have experience with this, sorry!
I hope i have helped!
Thank you so muche for your replies.
Concerning the brownies recipe, no milk in it, I took miss truly recipe on youtube, I already made them several times in the rectangular pan with no problems. Maybe it does not work out well in round pan.......I don't recall where I got the cream cheese frosting recipe, it should be at all recipes...
Yes, I think next time I'll stick to a "real cake" recipe. Got the comments from the lady who bought the cake and told me guests were satisfied with the taste of the cake that according to them was similar to "salame al cioccolato", an italian recipe where you use biscuits and cocoa to form a salami shaped cake. Oh well....
1) brownies, they are generally not smooth on top anyway. possibly werent cooked all the way through, that generally leads to sinking. most cakes can be cooked in any tin, u just have to adjust the time and temp, in my experience, brownies are trickier to adjust for.
2) most icing recipes you are going to do by taste/ eye int he final stages. if i add a whole tub of cream cheese, and include the liquid, i need more ps if i dont add the liquid, i need less. possibly the recipe is a bit off, or maybe u di dmis measure. (and if its mneasured in cups then you have whole new problems - packed cup, loose cup, sifted first etc etc)
3) if u reridgerate fondant (and many cream cheese icings need refridgerated, so the cake should b in the ridge too) then do not touch it until the condensation dries off.
4) press down hard and sharp. use a knife to tidy. try to avoid water (except as a glue), as it can leave marks, and make the fondant squidgy.
but yes, great cake especially or a first timer!
xx
if i add a whole tub of cream cheese, and include the liquid, i need more ps if i dont add the liquid, i need less. possibly the recipe is a bit off, or maybe u di dmis measure. (and if its mneasured in cups then you have whole new problems - packed cup, loose cup, sifted first etc etc)
That could have been the issue. The cream cheese we can get in the US is in foil-wrapped blocks, like a stick of butter, and doesn't have any liquid. So if you were using something with more liquid, then that's why the frosting was runny, if the recipe was for our kind of cream cheese.
I used philadelpia cheese, but probably yes, it's different from the cream cheese in the States. I think next time I'll drain the cheese before using it!
Apart from the result, not perfect at all, I think I learnt a great deal of things from making this cake.........and I'm quite satisfied with it. In the beginning I was quite discouraged as it seemed that every possible problem affected this cake but I learnt from my mistakes! (and your advice!)
Ours is Philly brand too but this is what it looks like: http://www.bigoven.com/uploads/CreamCheese.jpg
Yes, we have that too, but I got this: http://www.begcomunicazione.it/immagini_blog/philadelphia.jpg and there was some liquid in the bottom of the container...... 
So I finally ended my very first decorated cake, you will see the pics in my photos, and I'd like to discuss with you all the problems I had to face while making it, hoping I won't have to face them again!!!!
1- I made the cake with a brownies recipe, actually I made 2 of them. When they first came out of the oven they were perfect, no domes or anything, after a while they "deflated" and had this "hole" in the center of cake...Why?????
2- Filling for this cake was a creamcheese frosting. I followed the recipe carefully, but ended up with a very liquid mass and had to add tons of confectioners sugar. Recipe said I had to mix cream cheese and butter, then had to add the sugar. I used kitchen aid, can it be due to overmixing?
3- I made fondant from scratch the day before decorating. I did not know that I had NOT to put it in the fridge, so when I took it out it was quite sticky and had to add sugar to this too. How to recover a fondant that has been put in the fridge?
4- when cutting the decorations, all edges became sort of rough with small breaks, I tried to smooth them with my finger lightly dipped into water. How to obtain perfect crisp edges when cutting forms?
I hope you may answer my questions, and I hope I won't have to face these problems again, I really got so anxious about it, but I know cake making will eventually become fun......
1. Can't help with the deflation as I am still a hit and miss on that myself and havn't quite figured it out with cake mix let alone brownies
2. You may need to experiment with different recipes....I know I had to go through several versions of buttercream before I found one I can work with...
3. Yep, don't refrigerate fondant..even when its on the cake (Although I saw Cake Boss do it 
). After you make your fondant, cover the outside with some shortening, double wrap in saran (cling wrap) then place in a zip top bag and let rest on your counter overnight.
4. Your cake is beautiful..great job!! I would suggest rolling your fondant thinner for decorations. Make sure that your fondant is well kneaded before cutting. When using cutters you can turn them over, lay your fondant over the cutter then use your rolling pin to roll over the fondant covered cutter, this will give you cleaner sharper edges. If you use the cutter sharp side down, after pressing give the cutter a slight little wiggle in all directions, this will help to smooth the edges.
HTH
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