To prepare your margarita glass, run a slice of lime around the rim of the glass. Pour coarse salt on a plate and press the rim of the glass into the salt.
To a cocktail shaker, add Tequila Blanco, triple sec, sparkling water, sugar syrup, fresh lime juice, jalapeno, and ice. Shake till cold. Strain into your prepared glass. Added a thinly sliced jalapeno to garnish.
Note: if you love a spicy cocktail, add sliced jalapeno to the tequila, leave overnight for the spice to infuse.