Combine flour, sugar, cocoa, baking soda and salt in a large bowl. Add water, oil, vinegar and vanilla extract. Beat with a wire whisk or wooden spoon just until batter is smooth and ingredients are well blended. Pour into 2 - 8" round cake pans that have been sprayed with non stick vegetable coating spray. Bake @ 350 degrees for 20 to 25 minutes or until wood pick inserted in center comes out clean. Cool 10 minutes, then remove from pan. Cool completely on a wire rack. Just before serving, place 1 layer on serving plate and arrange 1 cup peach slices on top. Top with second cake layer and remaining peaches.