As I have mentioned before, I love to cook and try new recipes as well as make up my own. To the question about how do you make moist and sweet bakery goods the main thing to do is substitute some kind of softened fruit in place of the oil that is usually called for in most boxed or from scratch recipes. For example, unsweetened applesauce, baby food prunes so it has the texture of applesauce (this is great to bring out the taste of chocolate), canned pumpkin or a mashed up very ripe banana. All of these will make any cake or cookie moist. I have been doing this for several years and I have never been disappointed in the moistness of my baked goods. The good news with this is that it makes any baked good low fat automatically. So, experiment with the different fruits above that I mentioned.
My aunt (who is now deceased) gave me a cookbook using only Splenda. I have made many of the recipes from it and I will admit that I really gave it my best try. I agree with you that Splenda has its shortcomings. However, there are sugar-Splenda blends that might actually work although if it is the sweetness that you are missing then I would recommend adding dried fruit to the batter mix. Dried fruit is triple the amount of natural fructose (because the ripening process brings out the natural sugar in the fruit) and it really does the trick!
Just a note, there are 765 calories in one cup of white sugar. I can tell you that when I want a cookie, it is never just one! So, with that in mind, my latest “experiments” in the kitchen have involved trying to figure out the right amount of sugar for taste without having so much that it sends my blood glucose soaring. As I have been “studying” the ingredients in some of these recipes I have noticed that sometimes there is a duplication of some that really don’t need to be in most recipes. If you use self-rising flour for example, you do not need to add both baking soda and salt to it because the self-rising flour already has salt added to the flour during the processing of it. I heard that from a professional cook on a cooking program a few years ago. I did not know that!
Also, when looking at a recipe that calls for both commercially brand peanut butter (not the Smart Balance or the natural) reduce the amount of sugar that is also called for because there is already sugar in the peanut butter (like Jif or Skippy). So, lately I have decided that rather than go entirely no sugar (which I have done in the past for months on end) I am going more for lower sugar as long as the taste and texture are a close match to the original.
I just read recently that sugar also adds volume to baked goods and that if you use all Splenda expect your baked goods to come out flatter and not rise as well. I do use Splenda sweetened products when I know that having one with sugar is not the right choice for me. I also have to watch how added sugar (including natural fruit juices) impact my blood glucose so there is a place for Splenda in my food plan for that reason alone. However, I don’t think it is as good in baking (even though they claim that) as I would like. I like your idea of just using less frosting rather than 1″ layer. I just think sometimes with so many foods, it is a matter of doing away with the “overkill”: overly sweet, overly salty, overly greasy. It truly is a “cleaner way of eating”. In fact, it is now my preferred way of eating.