Here’s where the magic happens — turning humble ingredients into a delightful dessert. Just like the cooking lessons from my grandmother, I’ll guide you through each step:

1. Preheat your oven to 375°F (190°C) and line a 9×13 inch baking dish with parchment paper.
2. In a large bowl, combine the flour and granulated sugar. Cut in the chilled butter using a pastry cutter or your fingertips until the mixture resembles coarse crumbs.
3. Add cold water gradually, stirring until the dough comes together. Divide the dough into two equal parts, wrap in plastic, and refrigerate for at least 30 minutes.
4. Meanwhile, in a separate bowl, toss the sliced apples with brown sugar, cinnamon, nutmeg, lemon juice, and vanilla extract. Set aside.
5. Roll out one portion of dough on a floured surface to fit the bottom of your prepared baking dish. Gently press it into the dish.
6. Spread the apple mixture evenly over the crust. Roll out the second portion of dough and place it on top of the apples, sealing the edges with the bottom crust.
7. Brush the top crust with the beaten egg for a golden finish. Make small slits in the top to allow steam to escape.
8. Bake in the preheated oven for 45-50 minutes, or until the crust is golden brown and the apples are tender.