Loaded Mac and Cheese With Spinach

Name: Loaded Mac and Cheese With Spinach
Ingredients: 1/2 pound elbow macaroni, dry; 1/2 cup Marzetti® Garlic & Butter Croutons for topping; 6 tablespoons unsalted butter; 1/4 cup shallot or onion, finely diced; 4 tablespoons all-purpose flour; 3 cups warm whole milk; 2 1/2 cups grated Cheddar cheese or combination of Cheddar and Gruyère; 1 1/2 teaspoons ground mustard; Dash of hot sauce, if desired; 1 (16 ounce) frozen spinach, thawed and water squeezed out or 2 tightly packed cups fresh spinach; Salt and pepper