Bring a large pot of salted water to a rolling boil over high heat. Add the spaghetti and cook according to package instructions until al dente, typically around 8–10 minutes. Reserve ½ cup of pasta water before draining.

In a mixing bowl, combine shrimp with lemon juice and Old Bay seasoning. Allow to marinate while preparing the rest of the dish.

In a large skillet, heat 1 tablespoon of butter and 1 tablespoon of olive oil over medium heat. Sauté garlic for about 30 seconds until fragrant. Add marinated shrimp and cook for 2-3 minutes until pink and opaque. Remove and set aside.

In the same skillet, add 2 tablespoons of butter and melted. Add shallots and sauté until translucent. Add remaining garlic and cook for another 30 seconds.

Pour in the dry white wine and let it simmer for about 1-2 minutes until reduced to about 1 tablespoon. Stir in heavy cream, Parmesan cheese, and remaining Old Bay seasoning.

Add cooked spaghetti to the sauce, tossing gently to coat. If sauce is too thick, gradually add reserved pasta water until desired consistency is reached. Taste and adjust seasoning before serving.