The light fell from the sky in cataracts of pure transparency, in torrents of silence and immobility.
The air was blue, you could hold it in your hand. Blue.
—Marguerite Duras, The Lover
Happy Pi Day! I hope you had a slice to celebrate today.
This year’s pie isn’t even round. It’s a little quarter sheet pan slab pie.
I realized in hindsight that it doesn’t really count for the holiday since pi can’t even be derived from its measurements. But we’re too far in to go back now.
The pie keeps things simple and classic. It’s a juicy blueberry pie, fortified with plenty of lemon to brace the fruitiness. The filling is partially pre-cooked, to avoid spillage and a soggy bottom. Some sticky drips will still bubble up and escape through the lattice, but that’s part of the charm.
A brief moment for the lattice. This is a rather finicky, thin-stripped triple lattice that does require a fair bit of handling for the weaving.
For that reason, it’s best to aim for a pie dough that prioritizes flexibility over flakiness. This will also help it keep a more precise shape in the oven and minimize leakage.
To that end, this pie dough is actually made with 1:3 shortening:butter, which I rarely use. This decreases the flakiness by cutting the water (evaporation of which causes flakiness). It’s also worked a tad bit more prior to rolling out, to encourage gluten formation.
This makes a lovely, pliable pie dough that is good for finicky work. However, if such a precise lattice isn’t your priority, I would recommend sticking to a classic, all-butter crust, because personally, I love the shattery flakes of pie dough.
My go-to is, to no surprise, Stella Parks’ dough.
Pi day, previously:
2025: mocha chess pie à la Leda
2024: pie-stel de nata
2023: double chocolate almond pie
2022: Klimt klemon pie
2021: lime and coconut pie
2020: toasted black sesame pie
2019: black bottom cherry pie
2018: brown butter smoked salted honey pie
2017: vegan campfire pie
2016: brûléed citrus and lime pie
Pie, previously:
2023: squash pie
2018: plum and frangipane pie
2017: perfect peach pie
2016: pumpkin meringue tart
2015: apple, pear, butterscotch, and cheddar pie
2015: fig, rosemary, and lemon tart
2014: coconut buttermilk chess pie
2014: peach slab pie
2014: American pie
2013: Pumpkin spice brown butter chocolate pecan pie
Blueberry Slab Pie
dough recipe from Sally’s Baking Addiction
ingredients:
for the dough:
1.5x recipe of Sally’s pie crust
for the filling:
450 grams (2.5 cups) frozen blueberries
225 grams (2 cups) frozen wild blueberries
30 grams (2 tablespoons) lemon juice
175 grams (3/4 cup plus 2 tablespoons) sugar
1/2 teaspoon medium coarse sea salt
40 grams tapioca starch (1/3 cup plus 1 teaspoon)
directions:
When making the pie dough, pulse an additional 3-5 times so that the largest butter pieces are the size of a small pea and the mix is overall sandy.
Otherwise, follow the instructions to a T.
Divide the dough into 1/3 for the bottom section and 2/3 for the lattice and decorations; chill for at least 30 minutes.
Roll out the bottom portion and fit into quarter sheet pan.
Roll out and cut the lattice portion into 1/4 inch strips and put in the fridge to chill again.
Meanwhile, make the filling: combine all the frozen blueberries with roughly 1.5 cups of the wild blueberries, the lemon juice, sugar, and sea salt.
Toss to coat with 1/3 cup of the tapioca starch, leaving the remaining 1 teaspoon out.
Cook over medium heat for 10-12 minutes, until the juices are reduced and the mixture is thicker and syrupy.
Set aside 1 tablespoon of the blueberry syrup; allow both portions to cool.
Meanwhile, weave the lattice on a sheet pan: use 1 strip horizontally and 2 vertically; when the vertical strips pass over the horizontal one, cross one over the other to make an X.
On the next set of vertical strips, alternate which one has crossed over.
On the next row, alternate the direction of the X within the columns.
Overall, if in the first row, first column (1A), strip y went over strip z then in the first row, second column (1B), z goes over y; in 2A, z over y and in 2B, y over z.
Weave only as much lattice as you need to cover the quarter sheet pan; re-roll any scraps and use a rose cutter to make the roses.
Preheat oven to 350 degrees F.
Finally, to assemble, whisk an egg yolk and mix approximately 1.5 teaspoons of the yolk with the reserved blueberry syrup.
Paint whichever roses you want to be pink with the blueberry egg wash.
Toss the remaining frozen wild blueberries with the reserved 1 teaspoon tapioca starch and mix into the pre-cooked filling.
Pour all into the prepared bottom crust and top with the lattice.
Use the remaining egg yolk to generously egg wash the lattice.
Place the roses on top and bake for 45 min to 1 hour, until the juices are thick and bubbling on the surface; you may need to cover portions with aluminum foil midbake to prevent burning/overbrowning.
Allow to cool COMPLETELY before cutting into the pie.