Happy Pi Day! - No. 197

Let’s make some chocolate whoopie pies.

Chocolate Whoopie Pies from my book, American Cookie. Photo: Mitch Mandel.

JUST AS I WAS DUSTING OFF Irish bread recipes and admiring my green leprechaun hat in the mirror, I realized it’s Pi Day.

The day math nerds wait for, and three days before St. Patty’s. The green beer will have to wait. I’ve been hoping this newsletter might fall on Pi Day even more than National Brownie Day (Dec. 8) or National Boston Cream Pie Day (Oct. 23) so I could share one of my favorite chocolate ‘’pie’’ recipes that isn’t really a pie—Whoopie Pie.

It’s a cake that wants to be a pie.

Math lovers might not understand, but anyone who bakes will. And Whoopie Pies are not alone. Other cakes such as the Boston Cream and the cakey Shoofly masquerade as pie, too. (Wonder if that’s outlawed in Tennessee as well?)

The late Larry Shaw on Pi Day. He was a physicist and 1961 graduate of Reed College. He died in 2017. Photo: Reed Magazine.

So what exactly is pi day?

It’s the annual fete to celebrate a geometrical constant—the ratio of the circumference of a circle to its diameter. Have I lost you?

Pi’s precise value does not end but famously begins as 3.14159. And it’s observed today, March 14, because in the month/day format, the 3 for March and the 1 and 4 of fourteen are its first three figures.

Pi Day was founded by someone who didn’t just like math, but LOVED it…the late physicist Larry Shaw.

Thirty-five years ago, Larry Shaw, was at a retreat for employees of the Exploratorium, a science museum in San Francisco. He and his co-workers hatched a plan to link pi to the day March 14 and stage a mini celebration with their staff eating pie. The next year, the pi/pie party was open to anyone visiting the museum and they added a parade at 1:59 pm (don’t you just love math people?) Then they sang happy birthday to Albert Einstein, who really was born on March 14. Unfortunately in his native Germany, it would have been written 14/3.

In 2015, Shaw deemed it an extra-special, once-in-a-lifetime Pi Day due to the date—3/14/15–being the first five digits of pi. He felt the best thing about Pi Day was making math more accessible and fun for all.

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So what does this have to do with the adorable Whoopie - or Whoopee - Pie?

Absolutely nothing, but the pies are round so you could measure their circumference with a piece of string and divide that number by their diameter and see if you wind up with 3.14.

A 12-inch cheese pizza, a 10-inch pecan pie, and a 3 1/2-inch Whoopie Pie will all have the same answer - 3.14 or pi. And if not, fear not, because the two pillowy chocolate cakes sandwiched together with fluffy marshmallow cream filling will console you.

A whoopie pie is the stuff of dreams if you are a child or from the Northeast, or both. And if you talk with Mainers and Pennsylvanians as to who was the first to bake a Whoopie Pie, as I did when I wrote the book, American Cookie, each will claim the rights. Maine hasn't gone so far as to say the Whoopie Pie is its state dessert - that's reserved for the blueberry pie. But its residents do count the Whoopie Pie their "state snack."

I had to share this photo of a then young Ethan Reno of North Bath, Maine, eating as many whoopie pies as possible at a 2011 Heritage Days Festival. Apologies to his grown-up self. Photo: Getty Images.

Plus, there are differing stories as to how the name of Whoopie Pie originated.

The most believable is that it was named for the 1928 hit song called "Makin' Whoopee" by Gus Kahn. But this was three years after a Lewiston, Maine, bakery called Labadie's baked and advertised their chocolate Whoopie Pies. So, it might very well be a bakery confection that baked its way into the home kitchen.

Regardless of how you spell it or where it came from, Whoopie Pie is an American classic. It’s not going anywhere.

And pi isn’t either.

How do you celebrate pi day?

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Coming Thursday for Paid Subscribers

The best Irish raisin bread made from mashed potatoes and a little potato cooking water, how starch water improves the breads we bake, a conversation with Andrew Janjigian of Wordloaf, and a look at the fabled Irish cookery writer Theodora Fitzgibbon. Do not miss this newsletter. Not only is this bread perfuming my house, but I have learned the importance of starch water (and overnight stays in the fridge) in bread baking and you should, too.

What an amazing turnout at the Open Thread last Thursday! We problem-solved everyone’s kitchens and their appliances. It was a fun therapy session and opened my eyes to induction and Big Chill appliances. Even if you are working or busy when the thread begins, you can join anytime you like. I continue to check the questions and answers days later.

And now, without further ado, here is my pie for Pi Day!

Happy Baking!

- xo, Anne

THE RECIPE:

Chocolate Whoopie Pies

Wrap each cookie in plastic wrap until you’re ready to serve. They’ll keep up to 5 days at room temperature. If you don’t love the filling, substitute your favorite frosting—cream cheese, peppermint cream cheese, or mocha, with a teaspoon of instant espresso added to the buttercream. Or, opt for whipped cream, and store these in the fridge, or for ice cream, and keep them in the freezer!

Makes about 10 to 12 3 1/2-inch cakes

Prep: 40 to 45 minutes

Bake: 11 to 13 minutes

• Cake:

• 2 cups all-purpose flour

• 1/2 cup unsweetened cocoa powder

• 1 1/2 teaspoons baking soda

• 1/2 teaspoon salt

• 1/2 cup (4 ounces) unsalted butter, at room temperature, or vegetable shortening

• 1 cup granulated sugar

• 1 large egg, at room temperature

• 1 teaspoon vanilla extract

• 1 cup buttermilk, at room temperature

• Filling:

• 1/2 cup vegetable shortening or plant butter

• 1/2 cup (4 ounces) unsalted butter, at room temperature

• 2 cups sifted confectioners' sugar

• 2 cups marshmallow creme (fluff)

• 2 teaspoons vanilla extract

1. Place a rack in the center of the oven, and preheat the oven to 350ºF. Line two baking sheets with parchment paper, and set them aside.

2. Sift the measured flour and cocoa into a medium-size bowl. Stir in the soda and salt until well combined. Set aside.

3. Place the butter or shortening and sugar in a large bowl, and beat with an electric mixer on medium-high speed until creamed, about 2 minutes. Add the egg and vanilla, beating until combined. Scrape down the sides of the bowl. On low speed, alternately add the flour mixture and buttermilk, beginning and ending with the flour mixture. Scrape down the sides of the bowl. Dollop scant 1/4 cups of batter about 2 1/2 inches apart on the pans. With the back of a spoon, shape the batter into circles about 2 1/2 inches in diameter. Place one pan in the oven.

4. Bake the cakes until the tops are puffy and a toothpick comes out clean, about 11 to 13 minutes. Pull the parchment with cakes attached off the baking pan and onto a wire rack to cool. When the cakes are cool, run a metal spatula underneath and transfer to a serving platter. Repeat with the remaining cakes.

5. For the filling, place the shortening or plant butter, butter, sugar, marshmallow creme and vanilla in a large bowl. Beat on medium-high speed with the electric mixer until the mixture is smooth and well blended, about 1 1/2 to 2 minutes. Spread the flat side of half of the cookies with about 1/4 cup filling. Place the flat side of the remaining cookies on top. Wrap and store.