Place 4 ounces lemonade and 1 1/2 ounces vodka in a cocktail shaker. Fill the shaker halfway with ice. Seal the shaker and shake until the outside of the shaker is very frosty, about 20 seconds.
Fill an old-fashioned glass with ice, then pour in 1 teaspoon grenadine. Pour the cocktail through the strainer into the glass. Garnish with an orange slice and a maraschino cherry if desired.
