Make the strawberry syrup: In a medium saucepan over medium heat, combine the strawberries and sugar and bring to a simmer. Using a wooden spoon, stir the strawberries until they just start to break down and release their juices, about 10 minutes. Transfer to a nonreactive bowl and add the orange blossom water. Set aside in the refrigerator to chill.
Make the macerated blueberries: In a medium bowl, stir together the blueberries, cassis, sugar and lemon juice. Let stand at room temperature while you make the coconut syrup, stirring every minute or so.
Make the banana-coconut milk: In a blender, combine the coconut milk and bananas and blend until completely smooth. Transfer to a nonreactive bowl and set aside to chill in the refrigerator. (Note: The strawberry syrup, macerated blueberries and coconut milk can all be made a day ahead and refrigerated until ready to use.) 4. To assemble the dessert, place a few spoonfuls of blueberries in each glass. Scoop half a cup of shaved ice in each glass. Drizzle the banana-coconut mixture over the top until it has covered the ice, about ¼ cup for each glass. Top with remaining half cup of shaved ice in each glass and a spoonful of the macerated strawberries. Garnish with the toasted coconut flakes and serve immediately.