In a small saucepan over medium heat, place 1 cup water, 1/2 cup sugar and 2 tablespoons lavender flowers. Bring up to a boil, swirling to mix. Once it comes to a boil and the sugar is all dissolved, turn off the heat, and place the syrup aside to cool completely. Once cool, strain into a bottle or a mason jar.

To make the cocktail: in a shaker with ice, place the gin, simple syrup and lemon juice. Shake to chill (don't go too crazy, gin is delicate!), and then strain into a pretty coupe glass or champagne flute. Top with prosecco, garnish with a lavender sprig or a lemon twist and serve.