To make the pastry dough, combine the flour, cold butter, 1 1/2 teaspoons sugar, and salt in the bowl of a stand in mixer fitted with the paddle attachment. Mix in low speed, for 3 minutes or until butter and flour mixture resembles corn meal.

While it is still running in low speed, add cold water 1 tablespoon at a time and mix until the dough comes together, 30-45 seconds.

Transfer the dough to a lightly floured kitchen counter, divide it into 2 pieces and shape them into a 4-inch square. Cover them with plastic wrap and refrigerate for an hour.

Combine the rest of the sugar (2 tablespoons) and ground cinnamon in a bowl. Set aside.

To make the filling: Mix the cornstarch with water and set aside.

Heat butter in a 10-inch skillet. Add in the apples and cook, stirring occasionally, for 5 minutes or until they turn light golden brown.

Stir in the brown sugar, cinnamon, nutmeg, and salt, and cook for a minutes. Stir in the cornstarch, and cook for 2 more minutes.

Set aside to cool.

Pre-heat the oven to 350 degrees.

Roll one of the pastry dough into a 12X8 inch rectangle, 1/4 inch thick, on a lightly floured surface. Place it on a rimmed baking sheet covered with Silpat (read the blog post) or parchment paper. Keep it in the fridge, while you are rolling out the second dough.

Roll out the second pastry dough into a 12X8 inch rectangle that is 1/4- inch thick, on a lightly floured surface. Using a fluted pastry cutter, cut it into sixteen, 1/2-inch wide and 12-inches long strips.

Get the first dough out of the fridge and spread the apple mixture, making sure that the whole dough is covered evenly with the mixture. Arrange dough strips diagonally in lattice pattern over filling, trimming as needed. *

Using a sharp knife, cut it into 12 equal pieces. Space them 1-inch apart from each other. Brush the top of each cookie with egg, and sprinkle them with the cinnamon and sugar mixture.

Bake for 32-35 minutes in the oven, rotating the baking sheet halfway through baking.

Let them cool on the baking sheet before serving.