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

Combine chocolate bar, butter and boiling water in medium mixing bowl. Stir until chocolate melts. Combine flour, brown sugar, baking soda and salt in large mixing bowl.

Gradually add chocolate mixture, beating until thoroughly blended. Blend in eggs, sour cream and vanilla. Beat 1 minute at medium speed. Pour into greased and floured 13 x 9 inch pan. Bake at 350 degrees for 35-40 minutes or until cake tester comes clean.