In a large pitcher or mixing bowl, whisk together 1 cup fresh squeezed lemon juice and ½ cup granulated sugar until the sugar is completely dissolved.
Stir in 2 cups cold water until well combined.
Chill the homemade lemonade for at least 1 hour.
Add 1 cup of the chilled lemonade and 6 cups vanilla ice cream (approximately 12 scoops) to a blender
Blend until smooth. Pour into a cup and serve with lemon slices (optional).
Notes
You can use bottled lemon juice for this recipe. If using bottled juice, increase the amount to 1 ½ cups of lemon juice. This drink is best served immediately. You can store it in the freezer covered for up to 1-2 days.