Add flour to a medium bowl. Cut in butter and brown sugar with a pastry cutter or fork until particles are the size of small peas.
Sprinkle with cold water, 1 tbsp at a time and toss until all the flour is moistened and the pastry leaves the sides of the bowl. (You may not use the entire ⅔ cup water).
Cut the dough in half and gather into two balls. Shape each into a flattened round on a lightly floured surface. Wrap the pastry in plastic wrap and refrigerate for about 45 minutes or until the dough is firm and cold, yet pliable. If refrigerated longer, let pastry soften before rolling.
Roll one pastry round on a lightly floured surface, using a floured rolling pin. The dough circle should be 2-3 inches longer than your pie plate. Fold the dough in half and slid it over your plate. Unfold and ease it into the plate, pressing firmly against the bottom and side.
Roll the second pastry round on a lightly floured surface and roll out again to about a ¼ inch thickness. Take a cookie cutter and cut out a variety of dough shapes. Set them aside. Combine any scraps, re-shape into a ball, and repeat the roll & cut process until you have used up all the dough.
Heat oven to 425°F.
Peel 8-9 Granny Smith apples and slice them thinly.
In a large bowl, mix brown sugar, nutmeg, cinnamon, and flour. Stir in the apples until they are fully coated with the sugar & spice mixture. Spoon the apples into a pastry-lined pie plate.
Cover the top of the pie with the cut-out dough pieces to form a pattern as desired. Be sure that there are some holes or slits for the pie to vent while cooking.
Crack and lightly beat one egg (or mix maple syrup with water for a vegan version). Brush the mixture onto the top of the crust.
Cover the edges of the pie crust with foil to prevent burning.
Bake 40-50 minutes or until the crust is golden brown and juice begins to bubble through the slits in the crust.
Cool on a wire rack for at least 2 hours.
