Spinach Brownies

Why I Love This Recipe
There is not one ounce of chocolate in these brownies! My sister developed this recipe after sampling something like it in a local restaurant.
Ingredients You'll Need
1 cup flour
1 tsp salt
1 tsp baking powder
1 cup milk
1 stick butter, melted
2 eggs
10 oz frozen spinach (thaw and squeeze out extra moisture)
10 oz. pkg jack or cheddar cheese(or mix the two)
1/2 cup minced onion.
Directions
Mix together first 6 ingredients.
Add spinach, cheese and onion.
Pour into a 9" square baking dish.
Bake in 350 degree oven for 30 minutes.
You may double the recipe for a 9x13" pan.
To serve, cut into squares.