"torta glassata", then.
if it is "frosted" and it is cold (I mean for example made with ice cream) you could call it "dolce freddo con glassa".
Sorry Raimondo for the misunderstanding, just thought about a litteral translation...
But a cake made up with ice-cream is definetely a "Torta Gelato"
About the frosting, I'm not sure I've ever seen a frosted ice-cream cake, they are usually covered with cream ("panna"), and they are delicious!!
... let's stop talking about it, I'm starving!
glassa s.f. (cuc.)
1 (di zucchero) icing, frosting
2 (gelatina) glaze.
glassare v.tr. (cuc.)
1 (rivestire di zucchero) to ice, to frost
2 (coprire di gelatina) to glaze.
1 glacé, iced, glazed, candied
2 (estens.) (detto di indumento di pelle) patent.
glassatura s.f. icing, frosting, glazing.