Step 1

Fill a shaker half-full with ice. Add tequila, lime juice, and sweetener to the shaker. Seal and shake vigorously until outside is frosted, 10 to 15 seconds.

Step 2

Place salt on a plate. Run 1 lime wedge along the rim of the Mason jar. Press the jar down into the salt. Fill the jar with ice cubes.

Step 3

Strain margarita into the jar. Top with sparkling water and stir. Garnish with remaining lime wedge.