01 - In a cocktail shaker or large mixing glass, thoroughly muddle the fresh raspberries and cranberries until they are well crushed and their juices are released.
02 - Add the cranberry juice, raspberry juice, 1 tablespoon of simple syrup, and freshly squeezed lime juice to the shaker. Stir or shake vigorously to combine all ingredients.
03 - Fill two serving glasses with ice. Strain the mocktail mixture evenly into the glasses, distributing the fruit pulp as desired.
04 - Carefully top each glass with chilled sparkling water or club soda. Stir gently to integrate the sparkling component.
05 - Taste the mocktail and adjust the sweetness by adding more simple syrup if preferred.
06 - Garnish each glass with additional berries, a lime wheel, and a fresh mint sprig. Serve immediately for optimal refreshment.