I want to top a white choc. raspberry cake with raspberry filling with some sugared fresh raspberries.

only problem -- I don't know how to sugar the raspberries!

Anyone want to help a girl out??

I would just roll the raspberries in some pastuerized egg-whites and then roll those in granulated sugar, very gently.
That is how I do them.

HTH

room temperature/ constant temperature is the key. They will "sweat" from frig... room temperature, clean fruit, dry fruit, brush on a bit of whipped egg white, dust with fine granulated sugar, and even some luster dust. Air dry, again at room temp. Use as needed to decorate...

ok -so pasturized egg white-you mean like meringue powder mixed with water? sorry to be so silly about this I really have no idea.

egg white lightly beaten , and vanilla sugar (i make my vanilla sugar by adding 1 vanilla bean to a jar of granulated sugar, its good for a long time)
anyway, you brush your berries lightly with the egg white, roll berry on sugar, place on parchment paper lined tray fir about 1 hr. or until sugar is dry.

Thank You! I hope to have a very pretty dinner cake tonight!