In a mixing bowl, combine the cooked shrimp with lemon juice, olive oil, granulated garlic, and cumin. Toss well and let sit for 10 minutes.

Heat a skillet over medium heat and sauté the marinated shrimp for about 5 minutes until fully cooked. Let cool to room temperature.

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

In a large serving bowl, combine macaroni, sautéed shrimp, diced shallot, chopped celery, and parsley. Pour dressing over and stir gently.

Cover and chill in the refrigerator for at least 30 minutes before serving.