Make sugar-free cream soda by pouring club soda into a medium-sized glass or jug, filling it halfway. Add low-carb sugar and a splash of vanilla extract to the soda. Stir well until the sugar fully dissolves, mixing the flavour. Set this mixture aside for later.
Next, take your cocktail shaker and add fresh cranberries, a few sprigs of rosemary leaves, and a slice of orange if you want extra flavour. Use a muddler or the back of a spoon to gently press down on the ingredients, releasing their juices and aromas.
After muddling, pour in unsweetened cranberry juice, and if desired, a splash of fresh orange juice for extra zest. Add your choice of vodka and a handful of ice cubes to chill the mixture. Close the cocktail shaker securely and shake it vigorously for about 15-20 seconds to combine all the ingredients.
Prepare a tumbler glass with fresh ice cubes. Carefully strain the mixture from the shaker into the tumbler, filling it just over halfway.
To finish your drink, top it off with your homemade or store-bought sugar-free cream soda, pouring gently to keep the bubbles.
Garnish your cocktail with a slice of orange, a few whole cranberries, and a sprig of rosemary. This adds a nice touch and enhances the scent as you sip. Enjoy your refreshing drink—CHEERS!