Camillo Benso, the Count of Cavour, was a documented Italian nationalist; prior to running for elected office he had been founder and editor of Il Risorgimento, a daily newspaper published in Turin which had a marked liberal-nationalist slant.

That being said, it's important to note that Cavour was also a wealthy landowning aristocrat. Although he was an aggressive secularist and an economic liberal, on the whole he was socially very conservative. Somewhat indifferent to the monarchy, in his vision the state ought to be run by a select group of wealthy individuals. This put him at odds with the republicans both in Piedmont, mainly of Ligurian extraction (like Garibaldi and Mazzini) as well as political leaders in Milan, whose social importance should not be understated and indeed whose revolts had prompted Piedmontese intervention against the Austrian Empire. This caused no small degree of tension with the republican revolutionaries, who in late 1848 united the notions of liberal constitutionalism with Italian unity under the Piedmontese monarchy, having initially been largely in favor of a Napoleonic-style "Liberal State" which, depending on the different currents, might not have entailed the full unification of Italy.

Cavour might have had nationalist inclinations which had predated the acceptance of nationalism in Milanese intellectual circles, but it's important to point out that Nationalism for Cavour meant something very specific: once he became Prime Minister, when in 1853 new revolts broke out in Milan Cavour had no problem also arresting republicans in Piedmont, fearing that unrest would spread if he didn't. However, Cavour protested energetically when the Austrian authorities confiscated the property belonging to nationalist Milanese landowners who had taken refuge in Piedmont to flee the reactionist empire, and even recalled his ambassador from Vienna.

It's also true, though, that Cavour didn't have much of a plan with regards to Italian unification. The Piedmontese precedent of intervening in favor of the Milanese revolutionaries in 1848, established when Cavour was not Prime Minister and was only just elected to parliament, had set a broad policy of chipping away at Austrian power in Italy; but it's also true that the close ties between Turin and Milan made this policy more or less inevitable. The Piedmontese Participation in the Crimean War against Russia, the vehicle by which Cavour was able to get the Second French Empire to guarantee the defense of Piedmont, was a circumstance of happenstance more than anything: the Austrian Empire had actually been the first to ask the Piedmontese to join a potential war in Crimea, the logic being that by tying down a not insignificant portion of the Piedmontese army they would not take advantage of a distracted Austria and declare war. When the Austrians flip-flopped and backed out at the last minute, the other allies (Great Britain and France) were open to letting Piedmont participate anyway, and the French took it onto themselves to guarantee Piedmontese territorial integrity as an ancillary clause of the alliance.

For what it's worth, it's also important to take into account that the unification of Italy was a useful outlet through which Cavour could achieve two of his political objectives. Anticlerical to the bone and deathly fearful of a republican revolution, the unification of Italy could both refocus republicans, who had been the first to lobby for a unified Italy, as well as give Cavour a pretext to crack down on the clergy, and by extension, the Papacy; a powerful rival in Italy. Were these stratagems purely pragmatic, and was the final objective the strengthening of Piedmont? Not really: it is more accurate to say that specific politico-intellectual elite was strengthened regardless of their citizenship. That is to say, the new Italy was a state constructed to benefit of upper class, typically of the anti-clerical social conservative orientation. Of course, Cavour and indeed the Piedmontese establishment might very well have only set out to expel the Austrian Empire from Italy and absorb its clients, but that process nonetheless would entail a fundamental reengineering of the Piedmontese state. It was not difficult to expand this reengineering to encompass governance of all of Italy once the forces favoring unification of the whole peninsula became too strong to control.

My answer might seem unfocused; the fundamental issue is that Cavour was an able politician precisely because he was able to shift and refocus his policies to suit a limited set of simple convictions: laity, conservativism, and nationalism. And the broadness and malleability of the term "nationalist," which sometimes means anti-Austrian, other times means pro-Italy, makes for Cavour's intentions difficult to summarize. What little is clear is that he was dealing with forces favoring unification too great for him to control, and perhaps even comprehend.

The Italian Risorgimento by Lucy Riall (Routledge, 2002) is a good overview and my source for this answer. You might also be interested in Italy in the Nineteenth Century by John A. Davis (Oxford University Press, 2011) which is a more comprehensive examination of the whole century in which Italian unification is framed.