  We prove a formula expressing the Log Gromov-Witten Invariants of a product
of log smooth varieties $V \times W$ in terms of the invariants of $V$ and $W$.
This extends results of F. Qu and Y.P. Lee, who introduced this formula
analogously to K. Behrend. The proof requires notions of "log normal cone" and
"log virtual fundamental class," as well as modified versions of standard
intersection-theoretic machinery adapted to Log Geometry.
