Baked Spinach Artichoke Dip

Name: Baked Spinach Artichoke Dip
Prep time: 10 min
Total time: 10 min
Cuisine: American
Ingredients: 1 (8-oz.) block cream cheese, softened; 3/4 c. mayonnaise; 3/4 c. sour cream; 1 c. freshly grated Parmesan; 1 c. shredded white cheddar, plus more for topping; 1/2 c. shredded Gruyère; 1 (14-oz.) can artichoke hearts, drained and chopped; 1 (10-oz.) package frozen spinach, defrosted and chopped; 2 cloves garlic, minced; 1 tsp. lemon zest; 1/2 tsp. red pepper flakes; Kosher salt; Freshly ground black pepper; Baguette, for serving