Make wet walnuts: Stir 1/4 cup water and sugar over medium-high heat until boiling and sugar dissolves. Simmer until syrup turns a deep amber color, 6 minutes. Remove from heat; whisk in cream. Return to heat; stir until smooth. Add nuts and pour into a bowl; let cool.
Make chocolate sauce: Warm cream, butter and coffee until simmering. Remove from heat. Add chocolate; stir until smooth. Stir in vanilla; let cool.
Make pineapple sauce: Bring all ingredients and 1/3 cup water to boil over medium-high heat, stirring. Simmer, uncovered, for 30 minutes, until thickened. Pulse in a food processor until chunky. Pour into a bowl; cool.
Make strawberry sauce: Cook all ingredients in 1/4 cup water over medium heat, stirring, until strawberries begin to break up, 10 minutes. Pour into a bowl; cool.
Assemble splits: Divide bananas, ice cream and sauces among dishes; top with whipped cream and cherries.