Coat a 13x9 baking dish with softened butter
Slice bread and arrange in a baking dish in two rows, overlapping if necessary
In a large bowl, beat the eggs
Whisk in the heavy cream, milk, granulated sugar, vanilla extract, and cinnamon
Pour milk mixture over bread, pressing down lightly to be sure the mixture covers the bread
Cover with plastic wrap and place in the refrigerator overnight
Remove from refrigerator 30 minutes prior to baking
Preheat oven to 350 degrees F
Bake uncovered for 35-40 minutes or until browned and inside is set
Serve with powdered sugar, maple syrup or fresh fruit
Store leftovers in the refrigerator for up to 2 days