Preheat the oven: Set to 375°F (190°C). Lightly grease a 1 1/2–2 quart baking dish.
Prep the shrimp: Pat shrimp dry. Chop into bite-size pieces (about 1/2 inch) for even distribution.
Sauté quickly: Warm olive oil or butter in a skillet over medium heat.
Add shrimp, a pinch of salt, and half the Old Bay/Cajun seasoning. Cook 2–3 minutes until just pink. Do not overcook. Remove from heat and cool slightly.
Mix the base: In a large bowl, combine softened cream cheese, sour cream, and mayonnaise. Beat until smooth.
Add flavor: Stir in garlic, lemon juice, hot sauce, remaining Old Bay/Cajun seasoning, smoked paprika, black pepper, green onions, mozzarella, and Parmesan.
Fold in any optional mix-ins.
Fold in shrimp: Gently mix the cooked shrimp into the creamy base. Taste and adjust salt, heat, or lemon.
Assemble: Spread the mixture evenly in the baking dish. Top with a light layer of mozzarella and a sprinkle of Parmesan for a golden crust.
Bake: Bake 18–22 minutes, until hot and bubbling around the edges and lightly browned on top.
Finish and serve: Let rest 5 minutes.
Garnish with extra green onions or a dusting of paprika. Serve warm with your favorite dippers.