1. Preheat oven to 350°F. In a food processor, pulse spinach, artichoke hearts, sour cream, cream cheese and Cheddar to a coarse puree. Add lemon zest, salt and pepper and pulse to combine.
2. Transfer to a 1-quart ovenproof serving dish. Cover with foil and bake until heated through, about 35 minutes. Preheat broiler. Remove foil and broil spread until top is browned and bubbling, about 4 minutes. Serve hot or warm with crackers or crudités.
Note: Nutritional analysis is per serving of spread only.