I love baking.  I love math.  I love Pi Day!  When cooking/baking, I usually just try to make it taste good, but this year I wanted to make something that looked cool and tasted great.  I was inspired by the recent “cookie within a cookie” brilliance, and I decided that I needed to figure out how to put π into a pie.  

Step 1:

While brainstorming, this is the exact image that popped into my head….I just needed to find a way to make it happen!  I settled on a peanut butter pie with a chocolate π ring almost immediately.  I thought it would be relatively easy to dig trenches in the pie, and chocolate ganache seemed like an ideal filling.  First up: crust!

Step 2:

I used SmittenKitchen’s crust recipe as a guide (from the Brownie Mosaic Cheesecake, which is amazing! http://smittenkitchen.com/2007/08/alexs-choice/.)

8 ounces chocolate flavored animal graham crackers, finely ground

8 tablespoons unsalted butter, melted

1/2 cup sugar

1/8 teaspoon salt


1.  Preheat oven to 350. 

2.  Add chocolate graham crackers, sugar, and salt to bowl of food processor; process until fine. 

3.  While the food processor is running, drizzle in the melted butter. 

4.  Once you have a uniform mixture, dump the mixture into a 9-inch pie plate. 

Step 3:

Spread the crust mixture evenly across the bottom and up the sides of the pie plate, using the bottom of a measuring cup to press it in.  I tried to make the edge look pretty by using my finger to stop the crust from going too far up. 

Once you’re happy with your crust, bake it for ~8 minutes at 350.   Allow to cool.

Step 4:

I used The Pioneer Woman’s recipe for chocolate peanut butter pie.  http://thepioneerwoman.com/cooking/2009/06/another-pie/
She uses an Oreo crust – I’m sure it’s delicious, but I wanted something lighter.

1 cup creamy peanut butter

8 ounces cream cheese, softened

1 ¼ cup powdered sugar

8 ounces Cool Whip, thawed (I would have tried to substitute whipped cream, but she insisted that you use Cool Whip in order to achieve the proper texture.  I listened.)

Step 5:

Beat the peanut butter and cream cheese together until smooth.  Add the powdered sugar, and beat until smooth.  Add ~1 cup of Cool Whip, and beat until smooth.  Fold in the rest of the Cool Whip.

Step 6:

Add ~3/4 of the peanut butter mixture to the cooled pie crust; smooth the top, and try to make it as flat as possible.  Refrigerate the pie (and the remaining peanut butter mixture) for about an hour.

Step 7:

Once the pie firmed up a bit, I pressed the tops of a bowl (~5.5 inch diameter) and a ramekin (~4 inch diameter) into the top of the pie, making sure that they were centered.  These concentric circles would become the “legs” of my π. 

Step 8:

With my guides in place, I used various kitchen utensils to dig out my trenches (and added the filling to the remaining filling that was in the fridge).  The handle of this scoop worked pretty well, but I had to clean up the edges of the trenches with a knife.  Also, I tried to avoid digging all the way to the crust.   

Step 9:

The trenches ended up being a little under a centimeter wide – I knew that it would look better with skinnier trenches (legs), but during a trial run, I learned that it’s really hard to fill the skinny trenches.  So, wide trenches for me!

Step 10:

I then used a makeshift piping bag (filled with the leftover peanut butter filling) to add a circle to the middle of the pie (it's a little hard to see, but it's there!) and a peanut butter edge next to the crust.  These would act as dams and help create the top of the π. 

Once the trenches and dams were done, the pie went back into the refrigerator for 30 minutes or so – it softens really quickly!

Step 11:

Next up: ganache!

1/2 cup heavy cream

¾ cup chocolate chips

A handful of peanut butter chips

1.  Heat the cream just until it bubbles, and then add it to the chocolate and peanut butter chips. 
2.  Stir until melted and smooth, and allow to cool slightly.  I then filled my fancy squeeze bottle piping thing with the ganache and carefully filled the trenches. 

I would probably add more cream next time - a softer ganache would have been easier to cut. 

Step 12:

Rivers of chocolate ganache!

Step 13:

I then flooded the area above the trenches with more chocolate ganache (taking care not to go over the dams).  Again, it went back into the fridge for about 30 minutes.  I needed the ganache to be firm enough for me to spread the remaining peanut butter filling on top.

Step 14:

Once the ganache was firm, I spread the rest of the peanut butter filling over the top of the pie.  Here is where I should have stopped…..but I had extra ganache and decided to embellish the top of the pie. 

At this point, the pie went into the freezer until it was ready to be served -- I found that it was easiest to cut when frozen. 



Step 15:

The finished product!  As neat as this was, I would have considered it a total failure if the guests at my Pi Day party didn't eat it.  Luckily, it was delicious! 

Lessons learned:
1.  As I mentioned earlier, I would try to make a softer ganache next time - at room temperature, the peanut butter filling was way softer than the chocolate, making it impossible to neatly cut.
2.  The peanut butter filling was kind of sticky and softened quickly at room temperature.  Maybe a different pie would be easier to carve?  I also made a key lime pie -- that might have worked better, but I couldn't think of a filling.  Whipped cream, maybe?  

Thanks for reading!  :)
<p>Spectacular idea!</p>
Thank you!!
I made this pi pie last night. Brilliant idea. Mine didn't really work out--the pi symbol in the middle, that is. Luckily, I put a pi symbol on top so my co-workers would get it. :o) <br> <br>The pie was delicious, though. Next time, I'll do a trial pi pie and leave more time to make it. The filling gets soft really fast! Still really amazing. Thanks!
You're very welcome, and that's a lovely pie! I'm so glad people are still enjoying my pi pie. :) I wasn't sure if this idea would work and did a trial run first - that was how I figured out that I needed to keep putting it back in the freezer!
I heard you like pi, so i put pi in your pie so u can enjoy pie while u enjoy pi.<br><br>i just had to do that, the set up was too perfect.
Haha yes! I wish I could say that Xzibit was my inspiration, but I didn't even know about it until my brother said something to me.
Nerdiness, puns, and pies! Can this get any better? :D Thank you for sharing!
This reminds me of the first 8 seconds of this video:<br><br>http://www.youtube.com/watch?v=tKB4h9gvmm0
Thank you Stumbleupon for showing me this deliciousness!
Can you make one that's sugar-free for those of us who are pi-abetic? :D
I don't have a lot of experience with &quot;pi-abetic&quot; cooking or baking, but as a scientist, I love to experiment! I'll have to get back to you on that one...
Looooove this - so clever!!!
Thanks!! This might be the most artistic thing you'll ever see me do. :)
Very Creative and Imaginative! Looks wonderful! <br> <br>A Cheektowaga observer.....
I'm so glad you liked it! It's fun to know that baking is in my genes! :)
Phenomenol Pi <br> <br>Unbiased observer - Dr Py
I wonder who this could be! Thanks, Dad! ;)
you have got a ton if friends or something! almost 8000 views! yikes!!
I'm totally shocked by the number of views!! I don't how people are finding this....I thought I'd be lucky to break 100. :)
StumbleUpon. It's how I got here ^_^
That's awesome! A huge &quot;Thanks!&quot; to whomever stumbled upon this first, and many thanks to those who keep on coming. :) I hope people have as much fun looking at it as I had making it!
i am now starving!!!! looks delicious sarah :-)
Thanks, C! ;)
Hi! i really loved the pie! xD is so geek and fun hahaha, but i can give you an advice, when you will go to cook, and make a tutorial, i recommend you that don't use your nails in color, use them in natural, because that looks insanitary ^^
she is 1st place for right now on the pi contest i wish you luck
Actually, no The (App) le Pi my brothers has 2 votes, this has one, which came from me.
If I ever do this again, I'll definitely keep that in mind. It shouldn't be a problem, though -- as I noted, this is not my usual look! :) I'm glad you liked the pie!
Thanks for sharing! Amazing pie especially for my mathematician friends:)
I'm glad you enjoyed it - thanks!
This looks mathmagical! and delicious, you have piqued my curiosity on 2 fronts! excellent work!!
It's mathmagicaly delicious!
Awesome - thanks!
&quot;Mathmagical&quot; is my new favorite word -- thanks!
happy to share :) It's only fair, you share your delish peanutbutter Pi with us ;)
how clever
It looks tasty! And the Pi inside is fantastic!
Thank you! :)
Excellent work.
That's cool. Looks really good too.
Thanks! It was delicious - even the guests who don't love peanut butter agreed.
Just brilliant. I'm going to make this for my sons birthday. He knows Pi to 32 places (seems to go up every week).
That's awesome! I hope it turns out well. :) Happy birthday to your son!
Pi within pie. Head asplode.
Sorry? ;) Thanks for commenting!
His head asploded! Too much brilliance makes head asplode. Now brains everywhere.
haha very clever, and adaptable to a variety of pies!
Thanks! And yes, totally adaptable!
If you get a random knock at your door it will be me looking for this pi.=)

About This Instructable


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Bio: I bake to combat stress. I'm in grad school -- there's a lot of stress and a LOT of baking.
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