I just saw this gloriously tall cake scraper on Sweet and Saucy's FB page. It looks like it'd be amazing for frosting extended tier/double barrel cakes. Has anyone seen this for sale anywhere? Love the measurement marks as well.
I use a carpenter's 'set-square' tool as a cake scraper. I bought it at the hardware store.
It is a tool to help the carpenter get a right angle, so it is in an L-shape. The shorter end I put flat against the bench, and the tall side (which is at a precise 90 degree angle to the shorter end) is against the cake. It is 25cm high (which is about 10 inches) and has measurements on it.
So as long as I am holding the short end flat against the bench, I know the tall end scraping my cake is going to make the cake perfectly straight up and down. And because of it's height, it can do tall cakes also.
We've had some made up - i love them for Double Barrels etc... up to 12" in height.
Hope that helps!