Milito set Andrea Stramaccioni on the road to a ninth straight away win over Torino on league business - and a second win on the road this term - when he thumped a scorching shot into the net from 25 yards out on 13 minutes.
Substitute Cassano completed a comfortable enough evening for the visitors when he swivelled to bury the second from 10 yards out on 83 minutes after Milito had dummied fellow substitute Ricky Alvarez's ball into the home box seven minutes from time.
Inter lost 3-1 to Roma at home a fortnight ago, but will be enthused by the manner of their recovery. They are three points off joint Serie A pacesetters Juventus, Napoli and Lazio after three games of the campaign.
Torino's hopes of rescuing a draw from the evening appeared to evaporate when Rolando Bianchi drove the ball straight at Samir Handanovic from eight yards out when it looked easier to score while Riccardo Meggiorini thumped an effort wide as he dashed towards the opposition goal seconds later.
There was not much else for Torino to get excited about.
Milito has now scored five goals in six Serie A games against Gillet.
Alessandro Sgrigna also hit a post in the second half, but was deemed to be offside as it became clear Torino would suffer defeat for the first time this season.
Inter kept possession for large swatches of what was not the most memorable encounter with the gulf in class between the sides all too apparent especially in the midfield areas with Inter dominant.
Inter now turn their attentions to the Europa League and a Group H match against Rubin Kazan in Milan on Thursday evening.