We have had many good recipes for protein bars here. But the best/easiest one I ever got was a simple 3 ingredient plus water combo. I remember it not being in the recipe section so much as it in the tip section. I also remember the ingredients, but not the portions.
It was chocolate protein - ground flax seed - and all natural chunky peanut butter made into balls and frozen.
EDIT: I found the article/recipe by Chris Shugart
1) Bodybuilder Bon Bons
I learned this from fitness trainer Sandy Joyce. Take a whole jar of all-natural peanut butter and hand mix it with eight tablespoons of flax meal and three scoops chocolate Metabolic Drive.
The easiest way to do it is to just dump all the ingredients into a big bowl and mash 'em together with your grubby paws. Roll the 'dough' into balls, wrap in Saran Wrap or foil, and freeze. Makes around 37 balls.
These suckers are portable, healthy, easy to prepare, and make a damn good football game snack. My eight-year old daughter loves to make 'em and eat 'em too. Beats candy bars!