Make a mint simple syrup. In a small saucepan, combine 1/2 cup sugar and 1/2 cup water. Warm over medium heat, stirring, until the sugar dissolves. Remove from heat, add 1/2 cup mint leaves, and gently muddle with a spoon. Let steep for 15 minutes, then strain and cool.

Juice the lemons. Roll the lemons on the counter to loosen the juice, then cut and squeeze until you have 1 cup of fresh juice. Strain out seeds and most pulp for a cleaner sip.

Build the lemonade base. In a pitcher, combine the lemon juice with 1/2 cup cold water and the cooled mint syrup. Stir and taste. If it’s too tart, add a bit more syrup or water; if too sweet, add a splash more lemon juice.

Chill it down. Add a handful of ice to the pitcher or refrigerate for at least 20 minutes so the flavors meld.

Add the bubbles. Just before serving, pour in 3–4 cups chilled sparkling water or club soda. Stir gently to keep the carbonation.

Garnish and serve. Fill glasses with ice. Add a few fresh mint leaves and a lemon slice to each glass. Pour the spritzer, then lightly clap a mint sprig between your hands to release aroma and tuck it on top.

Optional cocktail twist. For an adult version, add 2 ounces of vodka or gin to each glass before topping with the spritzer. Stir once.