If your croutons are strictly for soups and NOT for salads you might want to come up with a name that reflects that idea more to avoid confusion.

Here are a couple of suggestions:

Souper Croutons
Soup Floats
Crouton Floats
Soup Toppers

You could also add another name in front of each of these like:

Mama's Crouton Floats

Good luck!