The boy and girl were born last week to a surrogate mother, the couple's rep told TV's "The Insider" Monday.
Bassett, 47, was a presenter at the 12th Annual Screen Actors Guild Awards in Los Angeles Sunday night and she recently finished shooting the movie "Akeelah and the Bee" with Laurence Fishburne.
Vance is a regular cast member on NBC's "Law & Order: Criminal Intent."
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