Zucchini Brownies oh my are these sooo good!

Zucchini Brownies


2 cups all-purpose flour
1/3 cup baking cocoa
1-1/2 teaspoons baking soda
1 teaspoon salt
2 cups shredded zucchini
1-1/2 cups sugar
3/4 cup vegetable oil
1/2 cup chopped walnuts
2 teaspoons vanilla extract

FROSTING:
1/4 cup butter or margarine
1 cup sugar
1/4 cup milk
1/2 cup semisweet chocolate chips
1/2 cup miniature marshmallows
1 teaspoon vanilla extract
1/2 cup chopped walnuts, optional

In a bowl, combine flour, cocoa, baking soda and salt. Combine zucchini, sugar and oil;
add to dry ingredients. Mix well. Stir in walnuts and vanilla. Pour into a greased jelly roll sized pan and bake at 350 deg.
Frost when cool. To prepare frosting:
melt butter with sugar and milk, stir in marshmallows and chips until melted, add vanilla and nuts if desired.