Preheat your galley oven to 350º. Butter a casserole dish or a 13- x 9-inch baking pan.
Melt 2 tablespoon of the butter in a small dish and set aside. Cut the rest of the butter into small pieces and set aside.
Drain the oysters, reserving the liquid in a separate bowl. Stir the cream and milk into oyster liquid and set aside.
Rough crush the crackers with your hands into a large bowl. Place one cup of the crushed crackers in a small bowl and stir the melted butter into that cup of crackers. That will be the last layer of the scalloped oysters and will brown nicely with the butter in it.
Begin the layering. Sprinkle bottom of prepared baking dish with 1 cup of the crushed crackers. Arrange one-fourth of the oysters, spaced a few inches apart, over crackers. Dab some butter pieces around the oysters and sprinkle with salt & pepper. Repeat layers 3 times using remaining crushed crackers, oysters, salt-pepper mixture, and butter pieces. Sprinkle evenly with reserved melted butter-cracker mixture. add a few more dabs of butter on top.
Pour oyster liquid-cream mixture over layered mixture in baking dish. Bake in preheated oven until puffed up, firm, and heated through, 35 to 40 minutes. Sprinkle with parsley. Serve hot or warm.