To your cocktail shaker, add ice, Jameson, peach schnapps, and pineapple juice. Add a splash of blue curacao, just enough to turn your cocktail green. Shake well to combine and chill.
Strain into 2 cocktail glasses over ice. Top each with 1 ounce of lemon-lime soda.
Garnish cocktails with a maraschino cherry and/or fresh mint, if desired.