2 (10 oz.) pkgs. frozen spinach
1 tbsp. butter
1 c. flour
1 tsp. salt
1 tsp. baking powder
16 oz. grated cheddar cheese
3 eggs
1 c. milk
1/2 c. chopped onion

Drain spinach. In large bowl mix all ingredients well. Add spinach. Put in greased 9"x13" pan. Bake at 350 degrees for 45 minutes. Cool. Cut into squares.