Mom’s Flat Apple Pie

 Mom's Flat Apple Pie isn't your traditional deep-dish affair; it's a generous sheet-pan version that serves a crowd, slices into perfect squares, and packs all the warm, spiced apple goodness of a classic double-crust pie—with a few delightful surprises along the way.

The secret lies in the crispy Corn Flakes base, which soaks up the juicy apple juices and prevents a soggy bottom crust. Tender Granny Smith slices are piled high, kissed with cinnamon and sugar, then baked under a golden, flaky top crust. A final drizzle of thin vanilla glaze adds just the right touch of sweetness. It's the kind of pie that disappears quickly at family gatherings—and leaves everyone asking for the recipe.
🥧 Mom's Flat Apple Pie

📝 Ingredients

For the Crust

• 3¾ cups all-purpose flour

• ¾ teaspoon salt

• 1½ cups shortening

• 1 large egg yolk

• Milk (enough to bring the egg yolk to 1 cup total liquid)

For the Filling

• 2–3 handfuls Corn Flakes cereal

• 10 Granny Smith apples, peeled, cored, and thinly sliced

• 1 cup granulated sugar

• 1 teaspoon ground cinnamon

• 4–8 tablespoons unsalted butter, cubed (use your judgment—more for extra richness)

For the Egg Wash

• 1 large egg

• 1 teaspoon granulated sugar

For the Thin Glaze

• ⅔ cup powdered sugar

• 2–3 dashes vanilla extract

• Milk (enough to reach a thin, drizzling consistency)
  

  👩‍🍳 Step-by-Step Instructions

  1. Make the Dough
  In a large mixing bowl, combine the flour, salt, and shortening. Use a pastry blender or your fingertips to work the shortening into the flour until the mixture resembles coarse crumbs. In a separate measuring cup, beat the egg yolk and add enough milk to reach exactly 1 cup of liquid. Pour this into the flour mixture and stir until a smooth, cohesive dough forms. Divide the dough into two equal portions—one for the bottom crust, one for the top.

  2. Prep the Pan
  Preheat your oven to 425°F (220°C). Lightly grease a 15×10-inch rimmed baking sheet (or a standard half-sheet pan). On a lightly floured surface, roll out one portion of dough to fit the pan, allowing a slight overhang. Gently transfer it to the pan and press it into the corners. (Don't trim the edges just yet—you'll seal them with the top crust later.)

  3. Layer the Crispy Base
  Sprinkle 2–3 handfuls of Corn Flakes evenly over the bottom crust. This humble layer is the genius behind this pie—it absorbs excess moisture from the apples and keeps the bottom crust delightfully crisp.

  4. Add the Apples
  Arrange the sliced Granny Smith apples in an even layer over the Corn Flakes, piling them up generously. They'll settle down as they bake.

  5. Sprinkle and Dot
  In a small bowl, mix the granulated sugar and cinnamon together. Sprinkle this mixture evenly over the apples. Scatter the cubed butter over the top—this melts into the fruit, creating a rich, caramelized filling.

  6. Top and Seal
  Roll out the second portion of dough and carefully place it over the apples. Trim any excess overhang, then fold the edges of the top and bottom crusts together and crimp with your fingers or a fork to seal tightly.

  7. Egg Wash and Vent
  In a small bowl, beat the egg with 1 teaspoon of sugar. Brush this mixture generously over the top crust—it gives the pie a beautiful golden sheen. Using a sharp knife, cut several small slits in the top to allow steam to escape during baking.

  8. Bake to Golden Perfection
  Place the pie in the preheated oven and bake for 25–30 minutes, or until the crust is deeply golden and you can see the filling bubbling through the vents. Keep an eye on it toward the end—ovens vary, and you want that perfect golden-brown finish.

  9. Glaze and Serve
  While the pie is still warm, whisk together the powdered sugar, vanilla, and enough milk to create a thin, pourable glaze. Drizzle it in a zigzag pattern over the entire pie. Let the glaze set for about 10 minutes, then slice into squares and serve warm—preferably with a scoop of vanilla ice cream or a dollop of whipped cream.

  💡 Pro Tips for Pie Perfection

  • Apple choices: Granny Smith apples are ideal for their tartness and firm texture, but you can mix in Honeycrisp or Braeburn for added sweetness and complexity.

  • Corn Flakes substitute: No Corn Flakes on hand? Try crushed graham crackers, vanilla wafer crumbs, or even plain potato chips for a sweet-savory twist.

  • Shortening vs. butter: Shortening makes for an exceptionally flaky, tender crust. If you prefer a butterier flavor, you can substitute half the shortening with cold unsalted butter, but the texture may be slightly less crisp.

  • Make ahead: You can assemble the pie up to a day in advance, cover, and refrigerate unbaked. Add an extra 5–10 minutes to the baking time if baking straight from the fridge.

  • Storage: Leftovers keep well at room temperature for up to 2 days or in the refrigerator for up to 4 days. Reheat slices in a toaster oven or conventional oven to restore that crispy crust.