Pre-heat the oven to 375°F.

Whisk together the cream, eggs, lemon juice, hot sauce, garlic and onion powders, salt, pepper and herbs.

Grease the bottom of a baking dish with butter.

Arrange an even layer of sweet potatoes on the bottom of the dish; top with a third of the onion, a third of the parm and a third of the cheddar. Repeat the procedure two more times, finishing with cheddar cheese.

Pour the cream mixture over the top and push the potatoes down to allow the cream mixture to be absorbed.

Cover with aluminum foil and bake for 45 minutes. Uncover and bake an additional 1 hour and 20 minutes, until the cream is absorbed and the top is brown. Let rest for 10 minutes before slicing.