Lightly spoon flour into dry measuring cups; level with a knife. Combine flour and next 4 ingredients (through salt) in a large bowl; stir well with a whisk. Make a well in center of flour mixture. Add milk mixture to flour mixture; stir just until moist.
Spoon batter into 12 muffin cups coated with cooking spray. Bake at 400° for 18 minutes or until done. Remove muffins from pan immediately; place on a wire rack.