Spinach-Cheese Squares - cooking recipe

Ingredients

1/2 stick butter
3 eggs
1 c. flour
1 c. milk
1 tsp. salt
1 tsp. baking powder
1 lb. Cheddar cheese, grated
1 (1 oz.) pkg. frozen spinach, drained
1 small onion, minced
6 medium mushrooms, chopped

Preparation

Melt butter in 9 x 13-inch pan.
Set aside.
Mix all remaining ingredients in a bowl.
Pour over butter.
Bake for 35 minutes at 350\u00b0.
Let cool before cutting.