1 (8 oz.) Hershey milk chocolate bar, broken into pieces
1/4 c. butter
1 2/3 c. boiling water
2 1/3 c. unsifted all purpose flour
2 c. packed, light brown sugar
1 tsp. baking soda
1/2 tsp. salt
2 eggs
1/2 c. sour cream
1 tsp. vanilla

Combine chocolate bar and butter and boiling water in medium mixing bowl. Stir until chocolate is melted. Combine flour, brown sugar, baking soda and salt in large mixing bowl. Gradually add chocolate, beating until thoroughly mixed. Blend in eggs, sour cream and vanilla. Beat one minute on medium speed. Pour into greased and floured 13'x9" pan. Bake at 350 degrees for 35 to 40 minutes or until cake tester inserted comes out clean. Cool completely. Frost as desired. 10 to 12 servings.