Don's Mix #2 or Don"s Spices
There are definitely classic and modern tiki drinks that call for these. You can easily make your own, assemble them from bought or housemade items, or buy them premade from BG Reynolds or other.
Don's Mix = 2 parts grapefruit juice to 1 part cinnamon syrup
Don's Spices = Equal parts vanilla syrup and allspice dram
If you love Tiki recipes, then they are worthwhile although I have only used Don's Spices in one recipe.
Don's Mix is very easy to make, it goes in a fair amount of classics, generally a small amount, if you use a jigger and use 1 - 2 oz or 2 oz and 4 oz that should set you up for all your drinks you need to make
have not made Don's Spices - it goes in very few tiki drinks, and probably takes some tinkering depending on if you are using st elizabeth or your own dram and how you made the vanilla syrup