In a skillet, heat 1 tablespoon of butter over medium heat. Add shrimp and cook for 2-3 minutes until pink. Remove and chop into smaller pieces.

In the same skillet, add another tablespoon of butter and increase heat to medium-high. Sauté thawed spinach for 2-3 minutes or until wilted. Drain any excess moisture.

Reduce heat to medium-low and melt 2 tablespoons of butter. Sauté minced garlic for 1 minute until fragrant. Mix in softened cream cheese until smooth, then add sour cream and mayonnaise.

Add onion powder, paprika, salt and pepper to the creamy mixture. Fold in sautéed spinach and prepared seafood, then mix in shredded mozzarella and grated Parmesan cheese.

Preheat oven to 350°F (175°C). Transfer mixture to an oven-safe dish and bake for 20-25 minutes until top is golden and bubbly.