To make ginger-cinnamon simple syrup: Finely grate 1 tablespoon of ginger (about a 1-inch piece). Add the sugar and water to a pot and bring to a gentle boil. Stir until the sugar has dissolved. Add grated ginger and cinnamon sticks to the pot. Turn the heat to simmer and put the lid on. Simmer for 15 minutes. Take out cinnamon sticks and strain syrup to remove grated ginger. Store in refrigerator for up to 4 weeks.

To make cocktail: Add non-alcoholic rum, blackberry juice, lime juice and ginger-cinnamon simple syrup to a cocktail shaker. Add some ice and shake until well combined and chilled. Strain into a tall glass filled with ice. Top with sparkling mineral water and garnish with citrus wheel and fresh rosemary.