Cook Italian sausage in a large pot over medium heat, breaking sausage up into small pieces. Remove sausage from pot and set aside.
Add butter to pot and melt over medium heat. Stir in flour and cook for 2-3 minutes.
Whisk in 1 cup of chicken broth. Once the butter/flour mixture is well incorporated, add in remaining chicken broth and milk.
Stir in potatoes, carrots, corn, onion powder, garlic powder, parsley, black pepper and salt.
Bring soup to a boil, then reduce heat to low and simmer until potatoes are cooked through, about 20-25 mins.
Stir cooked sausage into the soup. Simmer for a few more minutes to warm the sausage.