Add the pisco, cantaloupe juice, Simple Syrup and lime juice to a mixing glass, add large ice to a shaker tin, pour the contents of the mixing glass into the tin and shake vigorously. Taste for balance, then double-strain into a rocks glass over fresh ice. Garnish with a cantaloupe square wrapped in prosciutto and serve.
Combine the sugar and 1 cup water in a small saucepan and bring to a boil. Cook, stirring, until the sugar dissolves. Remove from the heat and let cool completely. Keep covered in the refrigerator up to 1 month.