Makes 2 large cocktails, or 4 small
Makes about 1½ cups of rosemary syrup
I grilled my peaches to bring out even more of their natural sweetness, but you could just as easily roast them in the oven (350 degrees F., until soft and oozing with bubbly juices). Or, if they are very, very ripe, leave them just as they are.
To make this drink into a sippable soda, suitable for the whole family, swap the prosecco for ginger ale, or sparkling water.