Apple Slab Pie

Ingredients

• 1 1/2 cups cold unsalted butter
• 3 cups all-purpose flour
• 1 1/2 teaspoons salt
• 1 tablespoon sugar
• 3/4 cup full fat sour cream
• 2 pounds mixed apples
• 1/2 cup sugar
• 1 tablespoon lemon juice
• 2 tablespoons cornstarch
• 1 1/2 teaspoon cinnamon
• Pinch salt
• 1 large egg
• 1 tablespoon milk
• Sanding sugar for sprinkling

Directions

1. Cut the cold butter into cubes, then let it sit for 5 minutes so it loses just a bit of that hard chill. In a large mixing bowl, whisk the flour, salt, and sugar together. Add the butter cubes and use your fingers to work them into the flour, pinching and rubbing until you have a coarse, crumbly mixture with a few bigger butter pieces still hanging around. Add the sour cream, then stir it in with a fork until the dough comes together in big curds.
2. Tip the dough onto the counter and gather it with your hands into one large ball. Use a knife to cut it in half, then press each half into a thick rectangle. Dust each rectangle lightly with flour, wrap it in plastic wrap, and chill it in the refrigerator for at least an hour or up to a day ahead, or freeze it and thaw it overnight in the fridge.
3. Roll 1 rectangle of dough into a thin rectangle about 11 x 15 inches, just a little bigger than your pan. Carefully move the crust into a quarter-sheet pan or jelly roll pan, pressing it gently into the corners. Let the extra dough hang over the edges by about an inch, and don’t trim it.
4. Move the pan to the refrigerator and chill the crust for 15 minutes.
5. Peel and core the apples, then cut them into 1/2 inch chunks. In a large mixing bowl, toss the apples with the sugar, cornstarch, cinnamon, and a pinch of salt.
6. Take the bottom crust out of the refrigerator and spread the apple filling evenly over it.
7. Take the remaining rectangle of dough from the refrigerator and roll it into a large rectangle about 10x13 inches, roughly the size of your pan. For a traditional top crust, lay the rolled dough over the apples, then roll and crimp the edges. Cut six vents in the top, three on the top and three on the bottom. For a lattice top crust, slice the rolled dough into strips and weave or braid them into a decorative lattice, then roll and crimp the edges.
8. Put the pie in the refrigerator and chill it for 30 minutes while the oven heats. Heat the oven to 375F.
9. In a small bowl, whisk together the egg and milk. Brush the egg wash over the top of the pie, then sprinkle with sanding sugar.
10. Set the pie on a larger sheet pan or baking sheet to catch any drips. Bake for 50 to 60 minutes, until the top is golden and the filling is bubbling in the center.
11. Let the pie cool completely before serving, about 45 minutes. The fully baked pie can also be covered with foil, kept on the counter, and served the next day. If you’d like, warm it briefly in the oven before serving. Leftovers keep wrapped in foil for about 2 days at room temperature or about 5 days in the refrigerator.