Spray an 8X8 baking dish with cooking spray.
Spread torn bread in an even layer in the prepared dish. Top with an even layer of blueberries.
Whisk together eggs, coconut milk, cinnamon, sugar, vanilla, and salt in a large bowl.
Pour egg mixture over the bread. Press down on bread pieces to make sure everything gets saturated. Cover with plastic wrap and refrigerate overnight or for at least 6 hours.
In the morning, preheat the oven to 350°F. Remove the casserole from the fridge, uncover, and top it with shredded coconut. Bake for 45-50 minutes until golden brown. Allow to cool slightly before serving.
Serve topped with syrup, whipped cream, or powdered sugar.