Combine all ingredients for the simple syrup in a large saucepan. Mix well. Set heat to medium-high. Stir, squish and chop the cherries with a wooden spoon or spatula until mixture reaches a full boil and thickens slightly, about 5 minutes.
Remove from heat and drain through a fine mesh sieve into a large measuring cup. Let cool completely, about 1 hour.
For the shaker:
Add ice to cocktail shaker until 1/2 full. Add in ingredients for the shaker, close, seal, and shake well until frothy (about 2 minutes).
Divide mixture into 3 champagne flutes.
To finish:
Dived lemon lime soda equally into champagne flutes by pouring over.
Garnish with lime slices, if desired.
Notes
DO NOT shake lemon lime soda in the shaker. It is carbonated and will likely explode or fizz out of your shaker making a sticky mess.Click here for my cocktail shaker.Click here for my champagne flutes. They're oversized and I love them!A friend wrote me to say that she made these sans-gin for Shirley Temple-esque treats for her kids and they loved them! She made the grownup version for herself. I loved this idea!