It's been a long time since my daughter has helped me out with a recipe, so yesterday when E volunteered to assist me with breakfast, I eagerly set her to work measuring and stirring. I had the recipe all worked out on paper, so I didn't think there'd be much opportunity for her to contribute creatively. As she does with any endeavor, she asked a thousand questions: "What's the difference between baking powder and baking soda?" "Why do you add salt when cake isn't salty?" "Why do you call...