Add the light rum, spiced rum, Kahlúa, Amaretto, and dark creme de cacao. Blend until everything resembles a slushee.
Add three scoops of vanilla cream. Puree again until the mixture resembles a milk shake. If the mixture is too thick, thin it out with a splash of milk. If you want a thicker cocktail, add another scoop of vanilla ice cream.
Pour the bushwackers into individual glasses.
Add whipped cream and maraschino cherries, if desired.