Preheat the oven to 375 degrees. Lightly butter a 9-inch square baking pan.
Cut the chilled butter into the walnut and cinnamon flour, with a pastry blender or fork until it is like coarse crumbs; set aside. Drizzle melted butter over cubed bread to coat, then toss with apples and raisins
Transfer apples and bread to a baking dish and top with walnut flour topping; bake for 45 minutes or until crisp. Serve hot or warm with ice cream.
Note that if you are starting out with fresh bread, then dry it out first in an oven