To make the concentrated coconut sugar simple syrup: combine 2 cups
coconut sugar with 1 cup water and simmer until sugar is completely dissolved. Allow to cool before using. Stores in the fridge for several weeks. (And while we're on the topic: I love the unexpected caramel sweetness from the concentrated coconut sugar simple syrup, but feel free to use a standard, white sugar simple syrup in its place if you want a more straightforward "sugar" sweetness -- or a clearer drink. Just adjust the quantity to taste.)
To take this from mocktail to cocktail: add a shot of your fave clear booze (I'd probably go the vodka route...) before topping with club soda. Enjoy!