My husband tries to bake his version of a Power Bar using GrapeNuts and peanut butter. Do you know how hard GrapeNuts are to chew even BEFORE you bake all the moisture out of them? Let me tell you, after they cool they're as hard to chew as, say, a piece of wood. To save my pearly new dental veneers, I'm going to copy this recipe and tape it to our pantry door. KC at PracticalHacks has provided the power bar recipe to save you money and give you control over ingredients, and the size of your bar (thus calories). The Clif Bars at Walmart sell for .89 per bar. These Do It Yourself energy bars range from .45 to .66 per bar, quite a savings if you're training like an Olympic athlete. Read here to see the very thorough recipe and nutritional breakdown.