4 cups (1 L) ice cubes
1/2 cup (125 mL) frozen lemonade concentrate
4 oz (120 mL) each vodka and limoncello
Peel and cube watermelon to make 4 cups (1 L); freeze until solid.
In blender on low speed, blend together watermelon, ice, lemonade concentrate, vodka and limoncello until ice breaks down.
Blend on high speed until smooth and slushy. Pour into pitcher. Garnish each serving with mint.
Nonalcoholic Slushy Watermelon Lemonade:
Replace vodka and limoncello with 1 cup (250 mL) water.