Creamy Lemon & Spinach Pasta Bake

Name: Creamy Lemon & Spinach Pasta Bake
Cook time: 1 h
Total time: 1 h
Cuisine: American
Ingredients: 12 ounces whole-wheat penne or rotini; 4 ounces reduced-fat cream cheese, softened; 1 tablespoon whole-grain mustard; 1 teaspoon grated lemon zest, plus more for garnish; 1 teaspoon onion powder; 0.25 teaspoon ground pepper, plus more for garnish; 0.25 teaspoon salt, divided; 2.25 cups half-and-half; 2 tablespoons extra-virgin olive oil; 0.25 cup chopped scallions; 10 cups packed fresh spinach (about 10 ounces); 1 teaspoon grated garlic; 1 cup shredded fontina cheese, divided; 3 tablespoons lemon juice