Muddle 2 sprigs (4 leaves) mint in mixing tin with Falernum and Cointreau. Add rum, lime juice, bitters, then shake. Strain into glass over a large cube. Top with ginger beer. Garnish with remaining mint sprig..
If you don't have Super Spice bitters, try Bittermens Tiki or anything with a cinnamon note. Alternative is to add a pinch of ground cinnamon prior to shaking (I didn't have any, so I used the bitters in its place).
Could also use a whole lime and muddle with the mint as in a traditional mojito preparation; I already had fresh squeezed lime ready so I used that instead. Could use regular simple or another sweet liqueur in place of the falernum, but I think it adds a great spicy note if you have it. And, of course, any regular rum can always sub for the rhum agricole
To make the tamarind puree, dissolve a small piece of brick tamarind in enough hot water, let it soften for a few minutes, then strain to remove seeds/fiber. Or use a small amount (1/2 tsp?) of tamarind paste.
The drink would probably work with reposado or anejo rum as the base spirit.
This tamarind mojito, w/alterations: https://food52.com/recipes/78415-a-beautiful-friendship-tamarind-mojito…