Preheat oven to 350 degrees. Thoroughly grease a muffin tin with butter. Whisk together the dry ingredients. Stir in the milk, vanilla and butter. Scoop the batter into the greased muffin cups, filling each cup with 2 tablespoons of batter. (This scoop
works perfectly.) Make sure the cups are no more than half full. Bake for 28-30 minutes.