Do you know what the date is, today?
March 14, 2015.
Which matches up with Pi and the first four numbers that follow its decimal point:
This is a once in a lifetime coincidence; the next calendar occurrence will be in 100 years in 2115! In order to mark the occasion, I spent last weekend battling intense jetlag (I had just gotten back from Asia) to test and bake a number of recipes to find one worthy of the celebration. I believe this baby is it:
Yes, yes, I know it's technically not a "pie" but instead a galette. Yes, yes, yes, a truer homage would have been to keep the pie in a circular shape (because Pi, after all, is the ratio of a circle's circumference to its diameter), as opposed to the oval above. But come on, cut me some slack! At this point, I was 3 test pies deep, running on about 5 hours of sleep, and just wanted to find a crust that was a) unfussy, b) allowed me to stamp out such HUGE numbers for Pi, and c) tasted good. Because I'm insistent on using all butter crusts (no shortening allowed in my household, them's the rules), the first two recipes that I tried had illegible numbers since the pie crusts kept shrinking. Oh well.
In the end, I used a heavily adapted version of Martha Stewart's pâte brisée recipe. Pâte brisée is basically French pie crust, but instead of blending the butter in by hand, the French instruct you to use a mixer or food processor to do so. The theory is that a food processor will better distribute the butter throughout the dough, which leads to a flakier, sturdier crust (most French patisserie tends to require a heartier crust to hold all the cream in the pastry). However, with a food processor, it's easy to overmix the dough, often leading to a crust that's dense and flat. I ended up finishing the mixing process by hand in order to avoid this problem. My resulting pie crust had a texture that was in between pâte brisée and traditional pie crust: a stronger, heartier crust that allowed me to stamp out and maintain my shapes, but also stayed true to the texture and flavor of good ol' American pie. Ace.
As for the filling, I was inspired by this blueberry caramel sauce recipe from Bon Appetit that I've had bookmarked for many years now. I worried that it might be too intense on its own, so at the last second I added in some Opalescent apple chunks to add some tart bursts of flavor here and there. My worries were in vain — the caramel flavor chilled out in the baking process and blended in wonderfully with the blueberries and apples. It's definitely a flavor combination I'll be exploring again soon!
Happy 3.1415 Day!!!
Some baker's notes:
- Not a pie baker? Me either. But I've done it enough times to be able to fake it — check out this salty honey pie recipe for some of my ultimate pie baking tips! Tips for this particular recipe include using the coldest ingredients and equipment possible (I froze my butter overnight before using, as well as stuck my food processor bowl and blade in the fridge overnight because I'm anal like that), flouring your work surface and equipment liberally, and yep, letting the dough rest overnight for a tender crust. Plan ahead for this one!
- Don't overdo the liquid in the pie crust recipe. When I was testing recipes, I found it difficult to make pie with a food processor because I would overshoot the liquid and end up with a crust was sticky, soggy, gooey and gross. It's hard to see how much you're adding to the crust when you use a food processor — this is why I have you stopping the food processor early and finishing the rest by hand. Use your judgement and add the liquid provided a tablespoon at a time, just until the dough starts to come together. Add only as much as that, and no more — you want to get to the point where it's still a little bit dry and you're having a little bit of difficulty keeping the dough together; it's okay to have a few pea-sized bits of dough fall off here and there as you're patting it together. Less liquid means a flakier, crispier and ultimately more tender crust.
- A note on the filling — it will seem like there's not enough filling for the pie, especially when you're spreading out the ingredients on the base before covering and baking. That's on purpose; I deliberately skimped on the filling because I wanted a larger crust to filling ratio, ensuring that each bite would have an almost equal amount of crust to filling. I like to think of this pie as a giant pop tart, basically. But if you're a traditionalist and want more filling than pie filling than crust, up the filling quantity by adding half of the amount provided to the filling's ingredients list.
- To stamp out the numbers, I used these Wilton alphabet and number cookie cutters. For clean, well-defined numbers, dip the sharp edge of each cookie cutter in flour before stamping out the shape.
Blueberry, Apple, and Caramel Pi Day Slab Pie
For the Pâte Brisée:
(makes 1 double-crust slab pie)
- 2 1/2 cups all-purpose flour
- 1 teaspoon granulated sugar
- 1 teaspoon kosher salt
- 1 cup (2 sticks) unsalted butter, cut into 1-inch cubes and frozen overnight (see baker's notes)
- 6 tablespoons ice cold water
- 2 tablespoons apple cider vinegar
For the Blueberry, Apple and Caramel Filling:
(makes enough for 1 double-crust slab pie)
- 3 cups fresh blueberries
- 1 medium apple, cut into 1/2-inch cubes (approximately 1 cup)
- 2 generous (small mound, unleveled) tablespoons cornstarch
- 1/4 cup caramel sauce
- a pinch of kosher salt
(makes enough for 1 double-crust slab pie)
- 2 tablespoons unsalted butter, cut into small specks
- 1 large egg
- 1 generous (small mound, unleveled) tablespoon granulated sugar
For the Pâte Brisée:
- In the bowl of a food processor, combine 2 1/2 cups all-purpose flour, 1 teaspoon granulated sugar, and 1 teaspoon kosher salt. Pulse for a few seconds until the ingredients are fully incorporated. Scatter 1 cup very cold cubed unsalted butter over the mixture, and pulse for a few seconds until the mixture resembles coarse meal, around 8 to 10 seconds total. DO NOT OVERPULSE.
- In a small liquid measuring cup, whisk together 6 tablespoons ice cold water and 2 tablespoons apple cider vinegar. You should have 1/2 cup of liquid. Grab 2 ice cubes, stick them in the measuring cup and whisk them ferociously for at least 10 seconds to chill the apple cider vinegar before fishing them out.
- With your food processor running, add 1/4 cup of the water and cider mixture in a slow, steady stream through the feed tube. Stop the machine when 1/4 cup is added, and pulse one or 2 times until the dough holds together — at this point, it's okay if the mixture still looks kinda dry and is just holding itself together with a few big chunks here and there. That's actually what you want. Use a rubber spatula to turn out the mixture into a large bowl. At this point, test the dough by squeezing a small amount together. If it is crumbly, sprinkle 1 tablespoon of water/apple cider (from the leftover mixture, you should have a cup left) and use your hands to mix until the dough comes together in a ball with some dry bits remaining. Squeeze and pinch with your fingertips to bring all the dough together, and, if necessary, sprinkle any dry bits with small drops of ice water to combine. Shape the dough into a flat disc, and use a bench scraper to divide it into two portions: one portion should be two-thirds of the dough (16 ounces, for those using a measuring scale), the other should be the remaining third (around 8 ounces). Wrap the portions in plastic and refrigerate for at least 1 hour, preferably overnight to give the crust time to mellow. Wrapped tightly, the dough can be refrigerated for 3 days or frozen for 1 month.
For the Blueberry, Apple, and Caramel Filling:
- When you're ready to make out the pie, make the filling. In a medium bowl, combine 3 cups fresh blueberries and 1 cup apple chunks. Sprinkle 2 generous tablespoons cornstarch over the fruit, and use a rubber spatula to gently toss the fruit until completely coated in the cornstarch.
- When the fruit has been dredged, drizzle 1/4 cup caramel sauce and a pinch of kosher salt over the mixture. Use your rubber spatula to toss the fruit until coated completely in caramel. Set aside while you roll out the pie dough.
- Prepare a large rimmed baking sheet (at least 15 x 10-inches) by lining with parchment paper. Set aside.
- Liberally sprinkle a work surface with flour. Unwrap the larger portion of dough (the 2/3rds one) and place it on the work surface, sprinkling its top with flour. This portion will be your base crust. If the dough is hard, let it rest for a few minutes. If the dough seems too sticky at first, add flour liberally. Use a rolling pin to roll with light pressure, from the center out, moving the pie dough around every quarter to roll it evenly. Roll the the dough to a rough oval that is about 15-inches long, 10-inches deep, and about 1/4-inch thick. Transfer this oval onto the prepared baking sheet and refrigerate while you roll out the remaining disk.
- Replenish your work surface with more flour. Repeat step 2, this time rolling the dough out to a smaller oval that is about 13-inches long and 9-inches deep. This portion will be your top crust. Transfer the rolled out dough on to a piece of wax or parchment paper. Use your numerical cookie cutters to stamp out the Pi number sequence, dipping the sharp edge of each cutter in flour before doing so. Once your numbers have been stamped, transfer the crust into the freezer to chill while you fill the bottom crust with pie filling.
- Remove the base crust from the refrigerator and use a spoon or a rubber spatula to transfer the fruit filling to the center of the crust. Spread out the filling evenly over the base, but leave a 2 to 3-inch border all the way around the oval. Evenly dot the fruit filling with 2 tablespoons of unsalted butter specks.
- Remove the top crust from the freezer and gently, carefully lay the crust over the fruit filling. There should still be a 1 1/2 to 2-inch border visible from the base crust. Working quickly, fold this border over the top crust, overlapping when necessary and pressing gently to adhere to the folds. Use a fork to press down on the border to "seal" and "crimp" the bottom crust onto the top crust. Transfer the pie to the refrigerator to chill while you preheat the oven.
- Center a rack in the oven and preheat the oven to 375 (F). While the oven is heating, whisk 1 large egg in a small bowl.
- When the oven is ready, remove the pie from the fridge. Working quickly, use a pastry brush to brush the top and border of the pie. Sprinkle evenly with 1 tablespoon granulated sugar and transfer immediately to the preheated oven. Bake until the crust is golden brown and filling is bubbling, 30 to 35 minutes. Transfer to a wire rack, and let pie cool until it is just warm to the touch, about 45 minutes. Slab pie is best eaten the same day it is baked, but it can be kept at room temperature, loosely covered with plastic wrap, for up to 2 days.