1. Soak cedar planks and skewers in water for at least 30 minutes or up to 2 hours. Meanwhile, in a shallow glass dish, combine vodka, brown sugar, 1 Tbsp. oil, mustard, salt and pepper. Add salmon and marinate 30 minutes.
2. Cut tomatoes in half lengthwise and scoop out the pulp and seeds. Holding 2 skewers about 3" apart, skewer 3 tomato halves with open side facing up; repeat with remaining skewers and tomatoes. Brush both sides with remaining oil. Remove salmon from marinade, reserving marinade to baste, and skewer in the same way as the tomatoes.
3. Coarsely shred 8 oz. Havarti; thinly slice remaining 4 oz. In a medium bowl, combine shredded Havarti, parsley and scallions; mound onto tomatoes.
4. Heat grill to medium. Alternate salmon and tomato skewers on planks. Grill covered, basting salmon with marinade twice, for 15 minutes or until salmon flakes with a fork. Top with sliced Havarti and grill 1-2 minutes until cheese is melted.