Preheat and prep: Heat your oven to 375°F (190°C). Lightly grease a small baking dish (8x8 or similar).
Soften cream cheese so it blends smoothly.
Mix the base: In a large bowl, combine cream cheese, mayonnaise, and sour cream. Beat until smooth and creamy.
Add flavor: Stir in Old Bay, garlic, Worcestershire, lemon zest, lemon juice, hot sauce (if using), and a pinch of salt and pepper. Taste and adjust seasoning.
Fold in cheese: Add Monterey Jack, cheddar, and Parmesan.
Mix to distribute evenly.
Gently add crab: Fold in the lump crab meat with a spatula. Keep the pieces chunky so you get hearty bites.
Finish with herbs: Stir in most of the green onions and parsley, saving a little for garnish.
Optional topping: Melt the butter and toss with bread crumbs or crushed crackers. Sprinkle over the top for a light crunch.
Bake: Spread the mixture in the dish and bake 18–22 minutes, until hot and lightly bubbling at the edges.
If you want a deeper golden top, broil for 1–2 minutes at the end.
Garnish and serve: Top with remaining green onions and parsley. Serve warm with your favorite dippers and lemon wedges on the side.