sorry but didn't understand. if you are buying a can of frosting, why add more sugar?

Ruchi0225....thats my question too. Why do you need to add to the bought frosting? If I'm gonna buy frosting, I'm going to use it straight out of the container.

I believe she's adding the powdered sugar to make the canned icing more stiff; so it's easier to pipe.

any ideas on how to build lil einstein rocket cake?

Store bought frosting is too thin to use for decorating a cake will hold it shape as well. the sugar is a stabilizer for a thicker frosting equal to professional bakery, Professional Bakeries use a Medium to Thick consistency for decoration

Actually that was supposed to read will NOT hold its shape