Add flour, sugar and salt in the food processor fitted with the dough blade and pulse a few times to mix.
Cube the butter and add to the flour mixture. Make sure butter is cold. Pulse several times until butter is about pea size and mixture resembles coarse crumbs.
Add cold water, 1 tablespoon at a time, and pulse until the dough starts to pull together.
Turn the dough out on a lightly floured board and shape into a disk. Wrap in plastic and rest in the refrigerator for an hour.
Roll the dough out to about 1/8” thick. Use a fluted edge or round cookie cutter about 2” or smaller and cut out the cookies. Reshape the left over dough and roll out to 1/8” again and keeping cutting out cookies until finish.
(Optional) Punch holes around the perimeters of the cookies with a toothpick.
Place the cookies on a parchment paper lined baking sheet and place the baking sheet in the freezer or refrigerator if your freezer is not big enough.
Preheat the oven to 400°F.
Beat 1 egg with 1 tablespoon of water or milk for egg wash, mix 1 tablespoon of sugar with 1/4 teaspoon of cinnamon for the sugar topping.
When the oven is ready, remove baking sheet from freezer or refrigerator, brush the top of the cookies with egg wash and sprinkle generously with cinnamon sugar.
Bake for 12 – 14 minutes until golden brown.
Remove from the oven, let cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.