A black hole must have opened up and stolen my protein powder, because I could not find it ANYWHERE, so I ended up using soyflour and powdered milk instead (1Tbs soyflour and then topped off the remaining 1/3 cup with powdered milk), which seemed to work reasonably well. Being far too lazy to melt chocolate chips, I just mixed about a Tbs in, which melted slightly and made chocolate swirls, which I'm pretty happy with. I didn't use the liquid sweetener and I used Sucanat instead of the Splenda. I did add the optional vanilla. I found them to be a little crumby, but I will give the recipe the benefit of the doubt and say its because I had to substitute for the protein powder. The real problem with these, for me, is the fact that they're not very transportable. And by that I mean, they need to be and stay refrigerated to be firm. The butter and peanut butter are much firmer at refrigerator-temperature than they are at room-temp, and the problem is, one of the great things about protein bars, IMO is that you have a healthy energy-boosting on-the-go snack. This is more something you can eat out of the fridge when you get home or as you're leaving, rather than something you could store in your bag to have whenever the need hits. I did find the flavor nice and the recipe couldn't have been much easier, but I don't think these are my homemade protein bars of choice. Worth a try, though!
I used fresh ground peanut butter, skipped the liquid sweetener and drizzled melted semi-sweet chips over the bars. Very good and my neice and her buddies have since polished them off. I'll definitely make these again.