Blackberry Margarita

Whisk lime juice and jam (or preserves) in a cocktail shaker or small measuring cup until blended and smooth. Add blackberries and muddle with a muddler or a wooden spoon, breaking the berries up slightly to release their juices.

Fill the shaker with ice; add tequila, orange liqueur and salt. Shake vigorously until the outside of the shaker gets icy, about 30 seconds.

Strain the mixture into 2 ice-filled rocks glasses. Top each with sparkling water and garnish with a fresh blackberry and a lime slice, if desired.