In a pot, combine citrus zests, ginger, spices, lavender, vanilla pod (if using), and water.
Bring to a boil, reduce heat, and let simmer gently for 20–30 minutes, uncovered.
Strain through a fine mesh or cheesecloth.
Return the liquid to the pot. Add sugar, molasses, citrus juices, and caramelized sugar. Stir until fully dissolved.
Add vanilla extract now (if you didn’t use a vanilla pod).
Stir in powdered kola nut, if using.
Let cool fully and store in a sterilised glass bottle or jar. Refrigerate for up to 2–3 weeks.
Mix 1 part syrup with 4 parts chilled sparkling water. Adjust the sweetness to taste. Garnish with citrus if desired.
