I think the recipe has a minor error in it and I also do a couple of minor tweaks.

First, for the chocolate I use two tablespoons of spoonable Splenda (that's not an error, just an alternative). I have also been adding about 50% more cream and Splenda than the recipe calls for because and it still seems a bit bitter - but isn't really noticeable in the finished product.

Second, for the peanut butter layer, I think you are supposed to put in 4 oz of heavy cream. I use an electric blender to mix it and use it on the high setting. It's so thick that it doesn't whip it, but it does make it a bit fuller. I have been backing off on the Splenda a bit her since it seems a little bit two sweet. I start with 1/4 cup and then add a tad if necessary.

Third, I make my own whipped cream starting with the 4oz of heavy whipping cream and adding the cocoa and Splenda to taste.