I am making a square alphabet blocks cake for my nephew. What kind of frosting do i use on the cake so that I can get sharp edges for fondant. I have to transport the cake to chuk e cheese in daytime. Temp might be around 80-90 and chuk e cheese is around 20-30 mins away. But the car has ac.
I need help!! Any tips on transporting are appreciated too.

I used an all butter based buttercream because once you chill it you can basically carve the icing by guiding along the edge of the cake board with a really hot scraper.

Ganache will get the corners sharper then buttercream!

I always use whipped white chocolate ganache under fondant.

I was just watching this video today by Cupadeecakes on you tube. She uses an all buttercream icing.

That first You Tube link has some nice sharp corners IF you want to spend an hour trying to ice one cake (crumbcoated off video, nearly 20 minute tutorial, waiting throughout three 10 minute freezing sessions, and more off video time to work on the top surface).

If you'd like "perfect sharp corners without even trying", check out the tutorial by BKeith that shows quick swipes using two spatulas.
How To Frost a Square Cake & Get Crisp Corners with Buttercream:
http://cakecentral.com/tutorial/how-to-frost-a-square-cake

I guess the "long and short of it" is that there are several different ways to accomplish "square" corners and the best way, is to look at all options, try them and see what works best for you. You might even discover a NEW technique along the way. What works for one might not work for another. And some decorators, like me, might never get the best square corners...but I just keep practicing!

Yep, that's why I linked to another option.

My background and experience is in production. When I see something that appears to be way too time-consuming, I try to avoid it. Finding more productive ways equals greater profits (and you can't continue doing what isn't profitable for very long).

Upside down! I'll be doing one tomorrow evening, and do not have the patience to try to square up corners. I let the board and the fridge do all the work for me.

Both. Usually SMBC though.

The only way they'd soften up is if someone smushed them. I'm taking a class with a Planet Cake instructor in October and will finally see how they do it...so excited!

I am counting the days. It's the madhatter class, and a large rose. 9 to 5 two days of nothing but ganache and mud cake. Ahhhhhhhh.

Thanks for all the advice guys. I have decided on chocolate ganache, just becoz I like the taste better than buttercream. I ll try the upside down method, becoz it looks faster. I really don't have the time and patience to freeze the cake so many times. Moreover I have three cubes to cover so I want it done fast. Anyways the cake is due 29th. So wish me luck guys.

I recommend ganache very highly.

It's at Baking Arts in San Francisco on the last weekend in September. The instructor is flying over. Go sign up, this is pretty awesome!

Lolll - i am going to be in SF at the end of september also - (following DH on a business trip) - not for any classes .

Bluehue

Oh my goodness, I wish I could afford to go to take this class!