Peanut Butter Chocolate Pie for Pi Day

You are going to HATE me for this, but you know what’s been going through my head all day today? Imagine this little ditty, if you will, sung to the tune of Rebecca Black’s “Friday”:

“It’s Pi Day, Pi Day, gotta eat pie on Pi Day, everybody’s looking forward to eating, eating. Eating pie, eating pie, yeah! Eating pie, eating pie, yeah! Yum yum yum yum, looking forward to eating pieeeee!”


You’re welcome.

Horrible earworms aside, isn’t Pi Day a fabulous idea? It takes a mundane day and a mathematical concept that holds absolutely no interest for me and somehow combines them to make a magical time where it’s appropriate—even encouraged!—to glutton out and feast on some mid-week pie. Yes please.


I actually made two pies for Pi Day, but I’ll be posting them separately for maximum Rebecca Black quoting opportunities. (Update: here’s the other one! Lime Coconut Pie) This first is a deep-dish Peanut Butter Pie. This baby has a chocolate cookie crust, a thin layer of whipped chocolate ganache, and a thick layer of peanut butter mousse. It’s topped with ganache, whipped cream, chopped peanuts, and peanut butter cups.


The whole thing was delicious, but the real star was the light, silky peanut butter layer. Traditional peanut butter pies are often made with Cool Whip (yuck) and cream cheese. We’re not big cheesecake lovers in this house, so I wanted to avoid creating anything that might resemble a peanut butter cheesecake. Instead, I used whipped cream and mascarpone cheese in the mousse, for a light, delicate texture that melts in the mouth.


Be warned that this pie is INTENSE. A small slice goes a long way! You could easily get 12-16 servings out of a 9” springform pan, so either invite all of your favorite friends over to feast on it, or be prepared to celebrate Pi Day all week long. Rebecca Black songs optional.

Peanut Butter Chocolate Pie
yield: one big beautiful 9-inch pie

Print This Recipe!

For the Chocolate Ganache:
8 ounces chopped semi-sweet chocolate
2/3 cup heavy cream
2 tbsp light corn syrup

For the Crust:
12 ounces Oreo cookies (about 26 cookies)
2 ounces (4 tablespoons) butter

For the Peanut Butter Mousse:
1 cup heavy cream
1 cup creamy peanut butter (not natural variety)
1 cup powdered sugar, sifted
1 teaspoon vanilla extract
1/2 teaspoon salt
8 ounces mascarpone cheese

To Garnish:
Whipped cream, chopped peanuts, extra ganache, peanut butter cups, etc

The ganache will need to cool for awhile, so it should be prepared first. Place the chopped chocolate in a heat-safe bowl, and combine the cream and corn syrup in a small saucepan over medium-high heat. Bring the cream to a boil, and as soon as it starts boiling, pour the hot cream over the chopped chocolate. Whisk everything together until the chocolate is melted and your ganache is shiny and smooth. Press a layer of cling wrap on top of the ganache.

The ganache now needs to cool until it’s the texture of peanut butter. You can leave it at room temperature, which will take several hours, or speed up the process by refrigerating it for 45-60 minutes.

While you wait for the ganache to cool, make the crust. Preheat the oven to 350 degrees Fahrenheit and spray a 9-inch springform pan with nonstick cooking spray. Place the cookies in a food processor and pulse in long bursts until they are in fine crumbs. Melt the butter and add it to the cookie crumbs, stirring until they’re evenly moistened.

Press the cookie crumbs in the bottom of the pan and up the sides about 2 inches. Bake the crust for 10 minutes, until it starts to puff and looks set but is not burned. Let it cool completely.

Once the ganache is thickened and the crust is cool, beat the ganache with a mixer until it is light, fluffy, and the texture of chocolate frosting. Spread it in the bottom of the cookie crust.

To make the peanut butter mousse, first whip the heavy cream until stiff peaks form, then transfer it to another bowl. In the same mixing bowl, combine the peanut butter and the powdered sugar and mix on medium speed until well-incorporated. (Mixture will be very stiff.) Add the vanilla extract, salt, and mascarpone cheese. Beat on medium speed until everything is well-combined. Mascarpone breaks easily, so don’t overwhip the mousse or leave the mixer running unattended.

Fold in 1/3 of the whipped cream to lighten the peanut butter mixture, then add the rest and gently fold everything together. Scrape the peanut butter mousse onto the whipped ganache, and spread everything into an even layer. Refrigerate the pie overnight, or for at least 6 hours until it is firm and set.

To finish it, garnish the top with whipped cream, chopped peanuts, chocolate peanut butter cups, or chocolate sauce. Store Peanut Butter Mousse in an airtight container in the refrigerator.


I’m linking this pie up at Crazy for Crust’s Pi Day Party!

29 Responses to Peanut Butter Chocolate Pie for Pi Day
  1. Allison says:

    So not cool to get that song stuck in my head so early in the day. But this pie might just make up for it. I like the inclusion of mascarpone in the mousse…it makes the Italian in me very happy. :)

    • Elizabeth says:

      Mwahaha…picture me twirling my mustache like an evil villain while watching Rebecca Black videos on a loop…

  2. My god, that pie looks like heaven on a plate. The mousse sounds divine. No way am I making this unless I have a party planned. It’s too tempting!

    • Elizabeth says:

      I shared it with two different groups of friends! On the one hand I was glad to have people to help me eat it, on the other hand I’m now very sad I don’t have any more pie…it’s a devil’s bargain.

  3. Orange Latte says:

    May I have 2 slices pleaseeee??? ^_^ Nice decoration!!

  4. Ambika says:

    Yum!! Love this!!

  5. brian says:

    yum i love peanut butter & chocolate pie, can’t wait to try this yummy recipe!

  6. Oh No!! Now that stupid song is ringing in my head!! Noooooo~ Btw, this is one of the most tempting pies i’ve seen all week…

    • Elizabeth says:

      So sorry! If it’s any consolation, it’s been in my head for about 3 days straight, and then it segues straight into Justin Beiber’s “Baby,” so I’m living in a very peculiar type of hell this week…

  7. I think I just died and went to heaven. This looks incredible! Do you think this could be frozen? My boyfriend isn’t a peanut butter OR a chocolate fan (sooo sad, I know), so there’s no way I could eat the whole thing in a short amount of time!

    • Elizabeth says:

      Thanks Raquel! And YES it can be easily frozen! I think the whipped cream topping is the only iffy part (it might separate or have a weird texture upon defrosting) but using cool whip instead or just leaving off the whipped cream decoration should work great.

      Also, do we need to talk about your boyfriend? Because someone who doesn’t like chocolate OR peanut butter sounds like trouble.

  8. myfudo says:

    Totally irresistible! Nothing can get better than this ultimate combo…Yummy! Can’t wait to try this recipe.

  9. Jodie says:

    This looks amazing Liz! I love that chocolate ganache is on the bottom!

  10. Kristen says:

    Found this on Pinterest and it looked so good I made it the next day. It was absolutely delicious and a cinch to put together! Thanks for the great recipe!

  11. Vanessa says:

    I’m making this later today for my hubby’s bday tomorrow. Just a question about the Oreos. Did you remove the creme and just process the cookie or did the whole cookie get pulsed up?

    • Elizabeth says:

      Sorry for the delayed response! Hope it’s not too late. I actually left the Oreos whole and didn’t remove the cream from the inside…faster, easier, and works great.

  12. Rachel says:

    Hi Elizabeth! I just wanted to let you know that I made this pie and talked about your blog and my delicious results on my blog today! You can check it out here:

    • Elizabeth says:

      Thanks for the head’s up! Your pie looked awesome. And from now on I am going to work “slap yo mama” into my regular food writing rotation.

  13. Sara says:

    Made this last night in preparation for my birthday today! It’s currently in the fridge awaiting release from the springform pan… any tips on a neat release? I haven’t used my springform with a side crust before and am worried the yummy oreos are going to get left behind when I open this up! Normally I run a knife around the edge, but I’m afraid I’ll break the crust.

  14. Grace says:

    Well, this is only the most beautiful looking pie EVER.

  15. [...] beginnings of what was to become an amazing peanut butter chocolate pie.  Heres the link.  Seriously, it was [...]

  16. Christy says:

    I know it been a while since you posted this but just wondering why no natural peanut butter? That’s the only kind we eat in my house. Is it just a texture thing?

    • Elizabeth says:

      Hi Christy,

      The problem is that natural peanut butters are just less consistent. Because they don’t have the emulsifiers that ‘regular’ pb does, some natural varieties may cause the mixture to separate or have a coarse or grainy texture. So to ensure the most consistent results, I recommend against it–I’d hate for someone to not have their pie turn out and lose all those ingredients. It’s very possible that your pb might work out fine, but it’s hard to know without trying the recipe with that specific brand.

      [PS When I eat peanut butter plain--on sandwiches etc--I only eat natural pb, but I do keep the 'regular' stuff around for baking and candy purposes. It works out pretty well that way!]

  17. Grace says:

    Hey! I want to make this pie for a bake off at school, but the problem is, they can’t be refrigerated there. So could I store it in the fridge over night and it still be good by the end of the next day? It is going to be sitting on a table for the whole school day, and I don’t want anyone to get food poisoning.

    • Elizabeth says:

      Hi Grace! I don’t think you’d really give anyone food poisoning after a school day at room temperature, but I still don’t think this pie is a good choice. It tends to get pretty soft if it’s held at room temp for long periods and I just think the texture wouldn’t be great after a day of sitting out. Sorry! I hope you’re able to try it another time. :)

      • Grace says:

        Thanks for replying!! Do you think that if I added some gelatin to the peanut butter mixture or left out most of the whipped cream it would hold up better? I really want to make this pie haha!! :)

        • Elizabeth says:

          I think a little bit of gelatin might help, and also swapping full-fat cream cheese (the bar kind, not the whipped kind) for the mascarpone would probably be the biggest help. If you do use cream cheese you might want to add a little more sugar because it’s not as mild as mascarpone–that’s optional though. If you use cream cheese and add a bit of gelatin and if the room isn’t too hot, you’ll probably be fine! Let me know how it goes. :)

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