Add frozen banana slices, crushed ice, rum, banana liqueur, fresh lime juice, and simple syrup to a blender.
Blend on high until smooth and thick. If too thick, add a splash of lime juice or water and blend again.
Taste and adjust sweetness with a bit more simple syrup if desired.
Pour into a chilled hurricane or tall cocktail glass.
Garnish with a banana chunk and a maraschino cherry; optionally add a light sprinkle of brown sugar. Serve immediately.
Notes
Frozen bananas create the creamiest texture—slice and freeze ahead. Use fresh lime juice for brightness. For a tropical twist, swap half the rum for coconut rum. Enjoy right after blending; leftovers can be re-frozen and re-blended.