Spinach Artichoke Dip Soup

Name: Spinach Artichoke Dip Soup
Ingredients: 1 ( 8 - ounce ) package cream cheese , at room temperature; 1 cup heavy cream; 2 tablespoons unsalted butter; 1 1/4 cups chopped yellow onion (from 1 medium onion); 2 teaspoons minced garlic (from 4 medium cloves); 1 teaspoon kosher salt; 1 ( 10 - ounce ) bag frozen spinach , thawed in a colander (Let moisture drip out as it thaws but no need to squeeze out excess.); 4 cups chicken broth; 2 (12-ounce) jars marinated quartered artichoke hearts , drained and coarsely chopped (about 2 1/2 cups ); 3/4 cup grated Parmesan cheese , plus more for serving; Freshly ground black pepper , for serving