In a large bowl, combine eggs, sugar, cinnamon, nutmeg, and vanilla whisk well to combine.
Add milk, heavy cream, and butter; whisk again to combine. Add raisins and pecans and stir.
Add bread pieces, and carefully fold to coat bread. Once coated, cover bowl with plastic wrap, and place into fridge for 30 minutes to 1 hour.
In a large slow cooker, place a rack in the bottom (I like to use 1-2 mason jar tops – without pop in lid, these work great as a ‘rack’). Add 1 cup of water to the slow cooker.
Using an oven proof souffle dish or glass baking dish (must fit in the slow cooker), grease liberally with nonstick spray or butter. Add bread mixture to bowl, cover tightly with foil, then top with slow cooker lid, and cook on high for 3-4 hours.
Remove lid, and carefully remove foil from the top. Allow to cook for 20 minutes.
Serve and garnish with additional raisins, pecans, and whipped cream if desired.