Make the simple syrup in a small sauce pot. Add all of the ingredients and bring to a simmer. Cook until the sugar dissolves and remove from the heat to cool completely. You will not need all of the simple syrup, so you can reserve the rest for another batch of Spicy Mango Margarita.
In a large pitcher combine the mango pineapple juice, peach nectar, simple syrup, sparkling water, and optional splash of tequila or vodka. Mix with ice.
Dip the rims of your margarita glasses in jerk seasoning.
Pour the mixture into each glass and garnish the rim with a lime wedge and a jalapeno slice. Serve right away
