Instructions:
In a bowl, stir together flour and sugar.
In a saucepan, combine water, 1/2 cup butter, and 1 1/2 ounces chocolate. Bring to a boil; remove from heat and stir in the flour and sugar mixture. Add eggs, sour cream, soda, and salt; blend well. Pour mixture into a greased and floured 10x15x1-inch jelly roll pan. Bake at 375° for 20 to 25 minutes, or until a wooden pick or cake tester inserted in center comes out clean.
For frosting, combine 1/2 cup butter, milk, and chocolate in a saucepan. Bring to a boil; remove from heat. Add powdered sugar and beat until smooth. Stir in vanilla. Frost chocolate squares while warm; sprinkle with chopped pecans. Cool and cut into squares.
