Zucchini Brownies

Directions

1. Preheat oven to 350°. In a large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Add eggs, 1 at a time, beating well after each addition. Beat in yogurt and vanilla. In another bowl, combine flour, cocoa, baking soda and salt; gradually add to creamed mixture. Stir in zucchini.
2. Pour into a greased 13x9-in. baking pan. Bake until a toothpick inserted in the center comes out clean, 35-40 minutes.
3. For frosting, in a small saucepan, combine chocolate chips and peanut butter. Cook and stir over low heat until smooth. Spread over warm brownies. Cool on a wire rack. Cut into bars.