(Optional Brine):
In a large pot, dissolve 1 cup kosher salt + ½ cup brown sugar in 4 cups warm water. Add zest of 2 oranges + 4 rosemary sprigs. Cool completely, add turkey breast, cover, and refrigerate 8–12 hours. Rinse and pat dry before cooking.
Preheat Oven to 375°F (190°C).
Pat the turkey dry, rub with olive oil, salt, pepper, herbs, and orange zest. Place skin-side up on a roasting rack in a pan.
Make Glaze:
In a saucepan, combine cranberries, orange juice, zest, honey, orange marmalade, garlic, rosemary, salt, and pepper.
Simmer 10–15 minutes until cranberries burst and mixture thickens. Reserve half for basting.
Roast:
Brush turkey with glaze. Roast about 20 minutes per pound, basting with glaze every 15 minutes during the last half hour.
Cook until internal temperature reaches 165°F (74°C).
Rest & Serve:
Tent turkey with foil, let rest 10–15 minutes, slice, and drizzle with remaining glaze. Garnish with orange slices and rosemary sprigs.