In her cookbook BakeWise, Shirley O'Corriher explains that adding whipped cream incorporates air into the batter (for a lighter cake), gives the cake a soft and silky texture, and adds a rich flavor.
All you do is whip a half cup of heavy cream to the soft peak stage and then fold this into your batter just before baking.
O'Corriher says that you can do this for just about any cake, muffin, or other tender baked good where you might want a softer texture. As she explains it, you don't need to make other ingredient adjustments. Just add a half cup of cream to the recipe and you're good to go!
If you live in fear of dry crumbly cakes, this technique just might be your ticket to sanity. Give it a try next time you bake a cake!