These are my vice on the Atkins diet... although they wouldn't be good to eat every day, due to the artificial sweetener and peanut butter, they are a great treat and a welcome alternative to the expensive, dry low-carb bars. (I think it tastes like peanut butter fudge, but that's just me)

2 cups protein powder (I use vanilla flavor, but you can also use chocolate flavor)
1 1/2 sticks butter (not margarine)
1 regular sized jar natural peanut butter (not lite or fat free, no additives)
1/2 cup Splenda

melt butter and peanut butter in microwave until smooth and creamy. Stir until blended. Stir in protein powder and Splenda and pour into a pan. Put in the refrigerator to set. (I let mine set overnight, it takes a while for them to firm up, and when they do, they have a fudge-like consistency)

Makes 12 bars

*(The original recipe is called the 4-3-2-1 recipe, but since I cut it in half, it's now a 2-1.5-1-.5 recipe) ;-D