For the Cranberry Infused Gin: At least 2 days in advance, place cranberries in a large mason jar. Muddle until slightly smashed.
Add gin, seal, and let sit at room temperature for 2 days. Strain and reseal. Infused gin can be kept in the refrigerator up to 1 month.
For the Popcorn Cream Syrup: Warm cream gently over a low heat with sugar, stirring until sugar dissolves. Salt popcorn liberally.
Place in a bowl.
Pour warm cream/sugar syrup over the popcorn, stir well, and leave to sit until cool. Cover and refrigerate 4 hours. Strain and keep refrigerated in a resealable bottle. Syrup can be kept in the refrigerator up to 1 week.
Add cranberry infused gin, Douglas Fir eau de vie, popcorn cream syrup, lime juice, and egg yolk to a cocktail shaker. Shake without ice to emulsify cream and egg, about 20 seconds.
Add ice to shaker and shake until well chilled, 15 seconds. Strain into a highball glass. Top with sparkling wine. To garnish, sprinkle chopped rosemary on top.