Spinach Squares
["2 (10 oz.) pkg. fresh spinach", "4 Tbsp. softened butter", "1 c. flour", "1 tsp. salt", "1 tsp. baking powder", "1 lb. shredded Cheddar cheese", "3 eggs", "1 c. milk", "1/2 c. chopped onion", "1/2 c. chopped mushrooms (optional)"]
["Wash, cook and drain spinach.", "Beat eggs.", "Add butter, flour, milk, salt and baking powder.", "Stir in cheese, onion, spinach and mushrooms.", "Put mixture in a greased 9 x 13-inch pan and level mixture.", "Bake at 350\u00b0 for 35 minutes.", "Remove from oven and cool for 45 minutes.", "Cut into bite size squares."]
["fresh spinach", "butter", "flour", "salt", "baking powder", "Cheddar cheese", "eggs", "milk", "onion", "mushrooms"]