Preheat oven to 325 deg F.
Whisk 2 eggs plus 4 egg yolks together. Set aside.
Over a low flame, combine 2 cups whole milk, 1/2 cup unsweetened cocoa powder, 1 1/2 cups heavy cream, 1 1/2 tsp cinnamon, and 1 tsp salt in a sauce pan until smooth.
Add 8 oz bittersweet chocolate, 1 1/2 cup sugar, and 1 tsp vanilla .
Slowly add milk-and-chocolate mixture to the eggs. Don't be aggressive! (If you do, you
will get scrambled eggs.)
Butter an 8" x 8" baking dish.
Cut 6-8 croissants into cubes and place in dish.
Pour chocolate mixture over croissants. Let them sit to soak up all the chocolatey goodness. Be patient!
Bake at 325 degrees for 45-50 minutes.
Scoop on some Cool Whip and eat!