1. Preheat oven to 375°.
2. Coat a 15 x 10-inch jelly-roll pan with cooking spray; dust with 2 teaspoons flour. Set aside.
3. Weigh or lightly spoon 9 ounces (2 cups) flour into dry measuring cups; level with a knife. Combine 9 ounces flour and next 4 ingredients (through salt) in a large bowl. Combine 3/4 cup water, 1/2 cup butter, and 1/4 cup cocoa in a saucepan; bring to a boil, stirring frequently. Pour into flour mixture. Beat with a mixer at medium speed until well blended. Add buttermilk, 1 teaspoon vanilla, and eggs; beat well. Pour batter into prepared pan. Bake at 375° for 17 minutes or until a wooden pick inserted in center comes out clean. Place on a wire rack.
4. Combine 6 tablespoons butter, fat-free milk, and 1/4 cup cocoa in a saucepan. Bring to a boil, stirring constantly. Remove from heat. Gradually stir in powdered sugar; stir in 2 teaspoons vanilla and pecans. Spread over hot cake. Cool completely on wire rack.
This recipe originally ran in Cooking Light March, 2000 and was updated for the November, 2012 25th anniversary issue.