In a large pot or Dutch oven over medium heat, cook the Italian sausage, breaking it into crumbles as it browns. Once fully cooked, drain any excess grease if needed.
Add the diced onion and celery. Cook for 4–5 minutes, stirring occasionally, until softened. Add the minced garlic and cook for another 30 seconds until fragrant.
Stir in the garlic powder, Italian seasoning, and smoked paprika until the sausage and vegetables are evenly coated.
Pour in the chicken broth and add the diced tomatoes and halved grape tomatoes. Stir to combine and bring the soup to a gentle boil.
Add the orzo and reduce the heat to a simmer. Cook for 8–10 minutes, stirring occasionally, until the orzo is tender.
Stir in the frozen spinach and heavy whipping cream. Simmer for another 2–3 minutes, until the spinach is heated through and the soup is creamy.