Preheat oven to 350-degrees Fahrenheit (190 degrees Celsius).
Liberally butter or spray the baking dish with baking spray, and set aside.
Cube the Italian bread and place in a large bowl.
Bring the milk, sugar, butter and vanilla to a low simmer in a medium size saucepan. Remove from heat and cool slightly.
Trim and cut the rhubarb and strawberries and add to the bowl with the bread cubes.
Add the blueberries and white chocolate chips to the bowl with the bread and rhubarb.
Toss to the ingredients in the large bowl to combine.
Turn the bread and fruit mixture out in an even layer in the buttered baking dish.
In a medium bowl whisk 3 eggs and a pinch of salt.
Slowly add about 1 cup of the warmed milk and butter mixture into the blended eggs. Stir to combine.
Pour the egg and milk mixture into the larger bowl with the remaining milk and butter mixture and stir well to combine.
Pour the milk and egg mixture (custard) evenly over the bread, fruit and chocolate mixture.
Press the bread into the custard so it is covered evenly.
Bake the bread pudding for 45 minutes in a preheated oven.
Remove from the oven and top the bread pudding evenly with the reserved ½ cup rhubarb, strawberries, blueberries and 1 tablespoon granulated sugar.
Return the bread pudding back into the oven and continue baking until the center of the bread pudding is set and it's puffed and golden (approximately 10 minutes).
Remove from the oven and serve warm do best flavor with vanilla ice cream, if desired (not shown).
Notes
Feel free to substitute the rhubarb, or leave it out entirely, if you're not a fan.Store any leftovers in an airtight container in the refrigerator for up to 5 days.May be frozen if stored in an airtight freezer container for up to 3 months.