Makes 2 dozen slices
THERE’S A FINE LINE BETWEEN APPLE PIE AND THIS RECIPE. ACTUALLY, I’LL LEVEL with you—I’m not sure there’s a line at all. What it comes down to is how this item is found in midwestern bakeries: on sheet pans the size of barn doors, slicked with icing, often called an apple slice or apple square, and eaten out of hand midday with no thought about it being dessert. So, this recipe being a pastry and not pie is a state of mind, is what I’m saying.
I was drawn to this recipe from a late 1970s University of Wisconsin–Madison cookbook because of its inclusion of crushed cornflakes, running a highly convincing campaign on the basis of kitsch and function. What you get here is a pastry dough that’s more forgiving than typical pie crust, and the ideal ratio of apple filling to crisp pastry, totally sog-proof thanks to that brilliant layer of crushed cereal, which magically disappears during baking. It’s the seventh wonder of the midwestern baking world.
2¾ cups/352 g unbleached all-purpose flour, spooned and leveled, plus more for dusting
2 tablespoons granulated sugar
1 teaspoon fine sea salt
1 cup/225 g unsalted butter, cold and cut into cubes
½ cup/113 g whole milk
1 large egg yolk
2¾ pounds/1.25 kg Granny Smith apples, peeled, cored, and thinly sliced (about 8 cups prepared)
⅓ cup/75 g firmly packed brown sugar
⅓ cup/67 g granulated sugar
1 teaspoon ground cinnamon
½ teaspoon freshly grated nutmeg
⅛ teaspoon fine sea salt
3 cups/85 g cornflake cereal, finely crushed (to equal 1 cup/85 g crumbs)
1 large egg white
Pinch of fine sea salt
1 batch Five-Finger Icing (here)
Prepare the crust: In the bowl of a food processor fitted with the steel S blade, combine the flour, granulated sugar, and salt. Pulse several times to blend. Add the butter cubes and pulse until the mixture appears crumbly.
In a small cup, whisk together the milk and egg yolk. With the processor running, pour in the milk mixture and blend until the dough comes together.
Turn out the dough onto a work surface and divide in half. Pat each portion into a disk, wrap each tightly in plastic wrap, and refrigerate.
Prepare the filling: In a large bowl, toss together the apples, brown and granulated sugar, cinnamon, nutmeg, and salt.
Position a rack to the center of the oven and preheat it to 400°F/200°C. Line a 12 × 17-inch/30 × 43 cm baking sheet with parchment paper.
Roll out 1 portion of dough into a rectangle slightly smaller than the pan. Place the dough on the parchment. Scatter the dough with the crushed cornflakes, leaving a 1-inch/2.5 cm bare border. Spread the apple filling over the cornflakes in an even layer, leaving the border bare.
Roll out the second portion of dough to the same size. Lay this dough sheet over the apples. Make a 1-inch/2.5 cm upward fold all around the perimeter, and crimp to seal.
In a small cup, beat together the egg white and salt until liquefied. Use a pastry brush to lightly slick the surface of the dough with egg white.
Bake until golden brown, 50 to 60 minutes. Let cool on the pan set over a wire rack for about 15 minutes. While still warm, glaze the top with Five-Finger Icing. Let cool completely before serving.