In a separate, clean bowl (or in my cleaned stand mixer bowl with the whisk attachment), I whip the cold heavy cream until it forms stiff, firm peaks. This is the step that gives the filling its light, mousse-like texture. With my spatula, I gently fold about one-third of the whipped cream into the peanut butter mixture to lighten it. Then, I carefully fold in the remaining whipped cream until no white streaks remain, being careful not to deflate the air. The filling will be thick, fluffy, and dreamy.
I retrieve my set crust from the freezer. I spoon the peanut butter mousse filling into the crust and smooth the top with my spatula. I tap the pan gently on the counter to remove any air bubbles. For the chocolate ganache topping, I heat the ½ cup of heavy cream in a small saucepan until it just begins to simmer, then pour it over the chocolate chips in a heatproof bowl. I let it sit for 2 minutes, then whisk until smooth and glossy. I let it cool for 5 minutes to thicken slightly before pouring it over the center of the pie. I use a spoon to gently spread it to the edges, letting some drip down the sides artfully. I garnish with chopped peanuts and chill the pie for at least 6 hours, or ideally overnight.
Pro Tips for Best Results
Ensure your cream cheese is truly softened. Leave it on the counter for a good 2 hours before you start. Cold cream cheese will leave tiny lumps in your filling no matter how long you mix. I’ve tried to rush this step, and the texture suffered. Room-temperature ingredients blend into a perfectly silky, smooth mousse.
Don’t overwhip your heavy cream. You want stiff peaks, but not butter! Stop when the beaters leave defined marks and the cream holds its shape when you lift the whisk. If you whip it until it looks grainy or curdled, you’ve gone too far and it may weep in the filling. I watch it closely once it starts to thicken.
When folding the whipped cream into the peanut butter base, be gentle and use a broad, sweeping motion with your spatula. You want to incorporate it fully while retaining as much air as possible. Deflating the cream will result in a denser, heavier filling. The goal is a cloud-like texture that still holds its shape when sliced.
Common Mistakes to Avoid
The most common mistake is using natural peanut butter. The oils separate and will create a greasy, unstable filling that won’t set properly and may even leak oil. I made this error in an early test, and while it tasted okay, the texture was all wrong and it made a mess. Stick with a homogenized, creamy commercial brand for guaranteed results.
Not chilling the pie long enough is a recipe for a soupy slice. The filling needs ample time to set up firm in the fridge. A minimum of 6 hours is required, but overnight is truly best. If you try to cut it after just 2 or 3 hours, it will slump and not hold its beautiful layered shape. Patience is a key ingredient here.(See the next page below to continue…)