1/2 cup packed fresh basil leaves, plus additional baby leaves for garnish
1 1/2 cups sugar
1 1/4 cups fresh lemon juice (from about 8 lemons) plus 2 tablespoons fresh lemon zest, plus additional zest for garnish
1/2 cup corn syrup
2 tablespoons limoncello
The tartness will vary depending on the lemons you use. Taste the mixed base once it is chilled. If it is too sour, add corn syrup a tablespoon at a time to meet your liking.