Slice bread into 1" thick slices and let dry on the counter for a couple of hours (or place in a 300°F oven for 10 minutes using caution not to brown the bread).
Place melted butter, brown sugar, and cinnamon on a large rimmed baking sheet (mine was 17.5" x 12.5"). Mix well and spread on the bottom of the pan.
Arrange bread in the pan over the brown sugar mixture.
Combine eggs, milk, vanilla extract, and maple syrup.
Gently pour half of the egg mixture over the bread ensuring all of the bread is soaked. Flip the bread and pour the remaining egg mixture over top.
Sprinkle with chopped walnuts and 1 teaspoon of cinnamon. Cover the pan with plastic wrap and refrigerate overnight.
Remove the pan from the refrigerator and let it sit on the counter for 20 minutes.
Preheat the oven to 350°F.
Bake for 30 minutes ensuring that the french toast doesn't brown.
Serve with maple syrup and whipped cream.
