Combine flour and next 4 ingredients in a large bowl.
Whisk together buttermilk and eggs. Gradually stir buttermilk mixture into flour mixture. Gently stir in butter. (Do not overmix; batter will be lumpy.)
Pour batter into a lightly greased 15- x 10-inch jelly-roll pan.
Sprinkle with pecans.
Bake at 350 for 25 to 30 minutes or until golden brown and done.