In a bowl, melt the butter in a microwave.
Place the cubed raising bread in the bottom of a 5 qt or 6 qt slow cooker.
Pour the melted butter over the top of the butter and stir well.
In a medium mixing bowl, whisk eggs, milk, cinnamon and vanilla extract.
Pour the egg mixture over the top of the cubed bread.
Allow the bread to sit for 1 hour to soak up the liquid.
Cover and cook on LOW for 4-5 hours or HIGH for 2 to 2.5 hours or until a fork comes out clean from the middle of the mixture and the sides are slightly brown.
Serve on WARM with maple syrup.