In a small bowl add the 4 tablespoons butter, brown sugar, 1 teaspoon of the cinnamon, nutmeg and walnuts. Mix with a fork until combined.
Cut the french bread into cubes and place into a large bowl
In a medium bowl whisk together eggs, milk, vanilla and 1 teaspoon cinnamon.
Pour the egg mixture over the cubed bread and toss until well coated. Cover with plastic wrap and let set at least 4 hours or overnight.
Rub 1 tablespoon of butter in the slow cooker. Place bread mixture in the slow cooker and sprinkle the crumb topping over the top.
Cook on low 6 hours or high 3 hours.
Serve with a sprinkle of powdered sugar, syrup and fresh fruit.