"Peace, land, and bread" was a distillation of the complicated Communist doctrine that the peasantry could understand and get behind. As it is a simple three word slogan, I doubt there's a "definitive" version. And as we see below, "freedom" or "liberty" often also show up in Lenin's writing.

"Peace, land, and bread" is often attributed to Lenin's The Tasks of the Proletariat in the Present Revolution, aka the April Theses of 1917 when the war was going disastrously for Russia. Nowhere is "bread" even mentioned (at least not in this translation), but the themes are there: end the war (still a hotly debated topic in April 1917), confiscate the land, set up collective farms to feed the people.

In our attitude towards the war, which under the new [provisional] government of Lvov and Co. unquestionably remains on Russia’s part a predatory imperialist war owing to the capitalist nature of that government, not the slightest concession to “revolutionary defencism” is permissible.

...

Confiscation of all landed estates.

Nationalisation of all lands in the country, the land to be disposed of by the local Soviets of Agricultural Labourers’ and Peasants’ Deputies. The organisation of separate Soviets of Deputies of Poor Peasants. The setting up of a model farm on each of the large estates (ranging in size from 100 to 300 dessiatines, according to local and other conditions, and to the decisions of the local bodies) under the control of the Soviets of Agricultural Labourers’ Deputies and for the public account.

Later in An Answer...

Foul slander against political opponents will help the workers to realise all the sooner where the counter-revolution is, and to sweep it away in the name of freedom, peace, bread for the hungry and land for the peasants.

In Lessons Of The Revolution...

Let us see, in fact, what the workers and peasants were striving for when they made the revolution. What did they expect of the revolution? As we know, they expected liberty, peace, bread and land.

In Draft Resolution on the Present Situation...

The whole course of events, all economic and political conditions, everything that is happening in the armed forces, are increasingly paving the way for the successful winning of power by the working class, which will bring peace, bread and freedom and will hasten the victory of the proletarian revolution in other countries.

In They Do Not See The Woods For The Trees...

Without the victory of the revolutionary proletariat there can be no peace for the people, land for the peasants nor bread for the workers and all working people.

That's just from his June - Sept 1917 works. You can find more in the Lenin Collected Works. Though keep in mind translation issues when trying to find support for an exact wording.

Finally in his October 1st, 1917 Letter to the Central Committee, The Moscow And Petrograd Committees and the Bolshevik Members of the Petrograd and Moscow Soviets we get...

The slogan is: Power to the Soviets, Land to the Peasants, Peace to the Nations, Bread to the Starving!

It seems land, bread, and peace were a common theme in Russian and Communist politics at the time. It appears several times in Trotsky's The History of the Russian Revolution...

“Land, bread, and peace” – those slogans [Lenin] could only have brought from Germany

...

Upon the proposal of Trotsky, the [Garrison] Conference adopted three short resolutions:

"The All-Russian Congress of Soviets must take the power in its hands and guarantee to the people peace, land and bread.”

...

Avilov, once a Bolshevik, a littérateur from Gorky’s paper. He conscientiously enumerated the difficulties standing before the revolution in the sphere of domestic and foreign politics. We must “clearly realise ... whither we are going ... Before the new government stand all the old questions: of bread and of peace. If it does not solve these problems it will be overthrown.”

See also...

• Lenin Collected Works