Pour the sugar into a shallow dish.
Take a slice of pineapple and run it along the edge of both glasses.
Dip the glasses into the sugar in the bowl to line the rim. Fill each glass with ice and set aside.
Pour the vodka, pineapple juice, lime juice, and grenadine into a shaker with ice. Shake for 30 seconds.
Divide the cocktail between the two glasses.
Garnish each cocktail with 2 slices of pink pineapple.