Spray a 1-1/2-qt. souffle dish with cooking spray; coat evenly with 1 Tbsp. Parmesan cheese.
Blend egg yolks, milk, cream cheese, cheddar and remaining Parmesan in blender on high speed 30 seconds or until smooth. Pour into large bowl.
Beat egg whites and cream of tartar in separate bowl with mixer on high speed until stiff peaks form. Gently stir into cheese mixture; pour into prepared souffle dish. With tip of spoon, make slight indentation or "track" around top of souffle 1 inch from edge to form "top hat."
Bake in a preheated 350º oven for 35 minutes or until top is puffed and golden brown. Serve immediately.