In a medium bowl, combine the cooked shrimp with lemon juice, olive oil, granulated garlic, and cumin. Stir until well coated and let marinate for about 10 minutes.

Heat a skillet over medium heat and add the marinated shrimp. Cook for about 5 minutes, stirring occasionally, until the shrimp are pink and opaque.

In a separate bowl, whisk together the sour cream, mayonnaise, Worcestershire sauce, brown sugar, mustard powder, salt, and pepper until smooth and creamy.

In a large bowl, toss the cooked macaroni with the sautéed shrimp, chopped shallot, diced celery, and parsley. Drizzle with dressing and gently stir.

Cover with plastic wrap and refrigerate for at least 30 minutes before serving.