1 28-ounce can crushed tomatoes
1 28-ounce can diced tomatoes
1 15-ounce can tomato sauce
1 ½ cups vegetable or chicken broth
3 cloves garlic, minced
1 onion, diced
2 tablespoons tomato paste
½ cup grated Parmesan cheese
1 ½ teaspoons Italian seasoning
1 teaspoon sugar
½ teaspoon salt
½ teaspoons freshly ground pepper
⅓ cup heavy cream
⅓ cup chopped fresh basil (optional)
Place all the ingredients except the heavy cream and basil in a slow cooker.
Stir until well combined.
Cover and cook on low heat for 6-8 hours or high heat for 3-4 hours.
Carefully puree with an immersion blender until the soup is smooth.
Stir in heavy cream and garnish with basil, if desired.