Recipe: No-Bake Peanut Butter Mousse Pie

Peanut butter pie made with peanut butter mousse or frosting and chocolate ganache
Peanut butter frosting is one of the best things I make, but the dark secret about this delectable topping is it's not really frosting. It's basically peanut butter mousse, or as I sometimes call it, "peanut butter whipped cream." I call it frosting because I will gladly smother any cake in this stuff, left, right, and sideways.

To make it, I start with two bowls. In one, I whip up a batch of cold whipped cream. In another, I blend peanut butter with powdered sugar and hot water and adjust it to reach the right sweetness and consistence (see my full recipe for peanut butter frosting).

Other people must love this recipe, too. It's one of the most visited pages on my blog. And sadly, I've been letting down a lot of people by not having a photo of the beloved peanut butter frosting/mousse/whipped cream.

To take a photo, I had to make a batch, and I did. But I don't have an oven at the moment because I'm waiting out a kitchen remodel that can't start for various reasons until September. No cake, no baking. So what could I do with this delightful PB stuff?

Well, I bought a bar of dark chocolate, melted it with cream to make ganache, buttered a round casserole dish, and spread it all around. Then I topped that with graham crackers and piled on the peanut butter filling. The filling makes the grahams soft and cake-like. The whole thing sat in the refrigerator for an hour or so, and then Boyfriend and I dove in.

It didn't quite work out as planned. The ganache was too hard. Drippy peanut butter mousse didn't hold its shape. But it did taste delicious. The rest of the "pie" is in the freezer. I'm hoping it sets up better so that if I defrost it for an hour in the fridge, it will keep its form better.

No-Bake Peanut Butter Mousse Pie
Serves 6 to 8
4 oz. dark chocolate
1/4 cup heavy cream (*I would suggest using more than 1/4 cup in hindsight)
butter for greasing
1 cup peanut butter
1/2 to 1 cup powdered sugar (confectioner's sugar)
a few tablespoons hot water
1/2 cup cold heavy cream (double cream)
1 tablespoon granulated white sugar
1 teaspoon vanilla extract
5 graham crackers
peanut butter and chocolate mousse pie
Butter a round casserole dish or pie dish. In a bain marie, melt the chocolate with 1/4 cup (or more) heavy cream, stirring and scraping the sides all the while. Remove from heat and let the chocolate ganache cool 10 minutes, then pour it into the buttered dish. Spread it evenly.

Break up graham crackers and set them in a single layer on top of the ganache.

In one bowl, blend the peanut butter using egg beaters or an electric mixer. Slowly add the powdered sugar. The mixer or beaters may struggle, so go gently on them. The mixture will become clumpy. Add hot water 1 tablespoon at a time until the peanut butter begins to smooth out and move again more easily in the beaters. Continue adding powdered sugar to taste.

In a second bowl using clean beaters or a whisk, beat the cream. Slowly add 1 tablespoon sugar and continue beating until you have soft peaks: that's whipped cream. It's better to err on the side of under-beating. You can always whip it more, but if you beat too long, you'll have butter, and you can't undo that.

Using a rubber spatula, fold a little of the peanut butter into the whipped cream. Add more and continue folding until both are fully blended. Spread this mixture on top of the graham crackers, and set the dish in the refrigerator for two hours so that graham crackers soften.

*Notes and adjustments: You can try freezing the pie and thawing it slightly in the refrigerator before cutting into six to eight slices with a hot knife and serving. Other adjustments: Lighten the ganache with more heavy cream (perhaps 1/2 cup total) and 1 tablespoon butter to give it a softer texture, as it was quite hard with 4 oz. chocolate to 1/4 cup cream.