It's obviously named after the relatively obscure 18th century Swiss scientist Blasé Rascal (not to be confused with the much better known 17th century French scientist Blaise Pascal).
Poor me, in doubt, I DuckDuckGo'ed "Blasé Rascal" :-)
Isn't that the right way, going back to the greatest compact dev env ever, turbo pascal!
Liam Neeson from "Batman Begins" approves of this pronunciation.
I almost found it insulting. But then I noticed the a.