Biden from the debate, with emphasis added:

And let me just ask a rhetorical question: If John really wanted to eliminate them, why is he adding to his budget an additional $4 billion in tax cuts for ExxonMobils of the world that, in fact, already have made $600 billion since 2001?
And, look, I agree with the governor. She imposed a windfall profits tax up there in Alaska. That’s what Barack Obama and I want to do.
We want to be able to do for all of you Americans, give you back $1,000 bucks, like she’s been able to give back money to her folks back there.
But John McCain will not support a windfall profits tax. They’ve made $600 billion since 2001, and John McCain wants to give them, all by itself — separate, no additional bill, all by itself — another $4 billion tax cut.

I’m almost sure that Biden is talking about McCain’s proposed reduction in corporate tax rates. Which isn’t at all the same thing as a special, “separate,” “all by itself” proposal to help the oil companies.