1/4 c. shortening
2 (1 oz.) squares unsweetened chocolate
1 c. sugar
1/4 c. peanut butter
1 egg
1/2 c. sourdough starter
1 tsp. vanilla extract
1/2 c. all-purpose flour
1/2 tsp. baking soda
1/4 tsp. salt
Peanut Butter Frosting (below)
1/2 c. chopped walnuts or pecans

PEANUT BUTTER FROSTING:

1 (1 lb.) box powdered sugar
1/2 c. unsweetened cocoa powder
1/4 tsp. salt
1 tsp. vanilla extract
7 tbsp. boiling water
6 tbsp. butter, softened
3 tbsp. peanut butter

Grease a 9-inch square baking pan or a 7 1/2 x 12 inch baking pan; set aside. Preheat oven to 350 degrees.

In a small saucepan, melt shortening and chocolate over low heat. Stir often. Stir in sugar and peanut butter until blended.

In a medium bowl, beat egg. Stir in sourdough starter, vanilla and chocolate mixture; set aside.

In a small bowl, stir together flour, baking soda and salt. Stir into sourdough mixture. Spread in prepared pan. Bake in preheated oven 25 to 30 minutes or until edges begins to pull away from pan. Cool slightly before cutting.

Prepare Peanut Butter Frosting. Spread over cooled brownies. Sprinkle with chopped nuts. Cut brownies and remove from pan. Makes 12 to 18 servings.

PEANUT BUTTER FROSTING: In a medium bowl, combine powdered sugar, cocoa powder and salt. Stir in vanilla and boiling water. Add butter and peanut butter. Beat until smooth. Frosting thickens as it cools. If it becomes too thick, stir in a few drops of hot water.