Egg wash: 1 large egg, lightly beaten with 1 TB milk
Optional: coarse sugar for sprinkling on top
10 cups peeled and chopped apples (a combo of Braeburn, Golden Delicious and Granny Smith)
2/3 cup granulated sugar
1/4 cup all-purpose flour
2 TB fresh lemon juice
1 tsp pure vanilla extract
1 1/2 tsp ground cinnamon
1/4 tsp ground cloves
1/4 tsp ground nutmeg
3/4 confectioners sugar, sifted
2 TB pure maple syrup
Enough milk or heavy cream to thin (a couple of teaspoons)
Make the pie crust: Mix the flour, salt and sugar together in a large bowl. Add the butter. Using a pastry cutter or two forks, cut the butter into the mixture until it resembles coarse meal (pea-sized bits with a few larger bits of fat). Drizzle the cold water across the mixture, 1 TB at a time, and stir with a rubber spatula or wooden spoon after every 1 TB added. Stop adding water when the dough begins to form large clumps. Transfer the pie dough to a floured work surface using floured hands. Fold the dough into itself until the flour is filling incorporated. The dough should come together easily and not be overly sticky. Form dough into a ball. Divide dough in half. Flatten each half into a 1” thick disc. Wrap each disc tightly in plastic wrap. Refrigerate for at least two hours.
Make the filling: Mix all of the filling ingredients together in a large bowl. Set aside.
Preheat oven to 375 degrees F.
Roll out the chilled pie crust. Remove the first disc from the refrigerator, keeping the other one in the refrigerator while you work. On a lightly floured work surface, roll the dough out into an 18 x 13” rectangle. Make sure to turn the dough about a quarter turn after every few rolls. Carefully place the dough into a 10×15” jelly roll pan. You will have overhang on the sides so trim it to about 1”. Smooth the crust so it fits nicely into the corners of the pan.
Spread filling evenly on top of crust.
Roll out the second disc in the same manner and size as the first. Drape over the filling and fold the bottom crust’s overhang over the edges. Seal them shut with your fingers and crimp down the sides with a fork that’s been dipped in flour. Cut slits into the top of the crust, then brush with a thin coating of egg wash. Sprinkle with coarse sugar.
Bake the slab pie for 40-45 minutes until the crust is golden brown and the filling is bubbling. Remove from the oven and allow to cool on top of a wire rack for a few hours.
Before serving, whisk all of the glaze ingredients together and drizzle over the pie. Cut into slices and serve.