Melt peanut butter, butter and cream cheese in microwave. Mix in Splenda and vanilla. Make sure everything is mixed well before adding protein powder. Add protein powder, 1/2 scoop at a time. You will need to use your hands towards the end. Press into a small casserole and chill until firm.
Makes 6 good size bars.
612 Calories (kcal); 63g Total Fat; (88% calories from fat); 9g Protein; 10g Carbohydrate; 186mg Cholesterol; 569mg Sodium