Preheat oven to 350*F (175*C). Grease a 13 x 9 x 2-inch baking pan; set aside.
Tear sweet bread into large chunks and place in prepared pan.
In a medium size bowl, whisk together eggs, milk, 1 1/2 teaspoons cinnamon, and salt. Pour egg mixture over bread and allow to soak for 5 minutes. Sprinkle with sugar, coconut and the remaining cinnamon. Drizzle top with butter.
Bake for 20 to 25 minutes, or until the bread has puffed slightly and is set.
Meanwhile, mix together sugar, salt and corn starch in a medium saucepan. Stir in mangoes and pineapple. Cook over medium heat, stirring constantly, until mixture begins to simmer. Cook until thickened and remove from heat.
To serve, cut casserole into squares and spoon sauce over individual portions.