Pat the salmon fillets dry with paper towels and season both sides generously with salt and pepper.
Heat olive oil in a large oven-safe skillet over medium-high heat. Place salmon fillets skin-side up and sear for 3-4 minutes until golden brown.
While the salmon cooks, combine cranberries, balsamic vinegar, honey, brown sugar, Dijon mustard, garlic, thyme, and broth in a small saucepan.
Bring the cranberry mixture to a boil over medium-high heat, then reduce to a simmer. Cook for 8-10 minutes, stirring occasionally, until cranberries burst and the sauce thickens.
Flip the salmon fillets carefully so they're skin-side down.
Spoon the cranberry balsamic glaze generously over each salmon fillet.
Transfer the skillet to a preheated 400°F oven and bake for 5-7 minutes, or until salmon reaches your preferred doneness (145°F internal temperature).
Remove from oven, let rest for 2 minutes, then serve with extra glaze spooned over top and garnish with fresh rosemary.