Cook and stir cream cheese product and milk in large nonstick skillet on medium heat 2 to 3 minutes or until cream cheese is completely melted and sauce is well blended. (Do not let mixture come to boil.) Gradually stir in spinach; cover. Cook 2 to 3 minutes or until spinach is wilted. Stir in half the shredded cheese.
Pour into 8-inch square baking dish sprayed with cooking spray. Combine cracker crumbs and remaining shredded cheese; sprinkle over spinach mixture.
Bake 10 minutes or until spinach mixture is heated through and sauce is hot and bubbly. Let stand 5 minutes before serving.
Spinach can hold a lot of dirt and must be thoroughly washed before using. To clean, fill a large bowl with water, then swish spinach around in water until most of the dirt comes off. Repeat process 2 or 3 times, using clean water each time, until no more dirt clings to the spinach. Rinse spinach thoroughly under running water. Remove hard stems; discard. Add leaves to salad spinner; spin dry. Or, pat leaves dry with paper towels.