In a medium saucepan, combine heavy whipping cream, stick of butter, cream cheese and parmesan cheese.
Simmer on low heat for up to two hours (at least an hour if possible). Simmer and stir until sauce has thickend and parmesan and cream cheese has melted completely. If sauce seems too thin add a little more parmesan cheese. (Sauce can be made in a small crockpot as well).
Place cod on a cookie sheet. Brush each piece of cod with the melted butter oil on both sides.
Sprinkle the buttered fish with the garlic salt (or powder) to taste. Cover pan of fish with foil.
Place cod in oven at 400 °F (200 °C) for about 45 minutes or until fish flakes easily with a fork.
To serve, place fish on a plate and generously spoon some Alfredo sauce on top of the fish.
Serving suggestions: dish is great served with steamed broccoli or grilled zucchini and yellow squash.
There are 765 calories in 1 serving of Baked Cod with Alfredo Sauce.