Preheat the oven to 175°C. Lightly spray a casserole dish with nonstick cooking spray. In a large bowl, add the bananas, strawberries, milk and sugar, and gently mash. Allow the mixture to macerate and come to room temperature. Add the raisins, cinnamon, salt, egg and egg white, and mix together.
Cube or tear the donuts and place in the prepared casserole dish. Cover with the liquid mixture. Bake until the center has jelled, about 1 hour. Garnish with fresh fruit slices.