In a cocktail shaker, muddle rosemary sprig and orange peel to release oils. Add vodka and muddle until combined and fragrant, about 30 seconds.
Strain into an ice-filled copper mug. Add orange juice and cranberry juice and stir until cocktail is cold and condensation forms on outside of cup, about 30 seconds.
Top off with ginger beer. Garnish with orange wedge, cranberries, and rosemary sprig.
