Slice bread into 1″ thick slices & 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, & cinnamon on a large rimmed baking sheet about 17″ x 12″. Mix well and spread on the bottom of the pan.
Arrange bread in the pan over the brown sugar mixture.
Combine eggs, milk, vanilla & maple/rum extract.
Gently pour half of the egg mixture over the bread ensuring all of the bread is soaked. Flip the bread & pour the remaining egg mixture over top.
Sprinkle with chopped nuts (if using) & 1 teaspoon of cinnamon. Cover the pan with plastic wrap & refrigerate overnight.
In the Morning
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 until a GOLDEN brown.
Serve with butter & other items on your French Toast Board.