Archie Thomas includes this recipe in the "mocktail" section of his book. Since we don't play that way, we added rum. Other than that, the recipe is the same and can be found in the book 50 Amazing Cocktails Inspired by Harry Potter.
Professor's Pineapple Pop (named for Professor Pomona Sprout from Hufflepuff)
2 parts rum
1 teaspoon sugar
1 tablespoon honey
2 parts pineapple juice
Add everything but the soda water to a blender. Blend together then sir in soda. Strain into glass. Garnish with coconut slice.
Harry Potter and all other characters/places/houses/etc. are the property of J. K. Rowling.