In a bowl, combine flour, a tiny pinch of salt and cornstarch. Set aside.
Beat butter and sugar until light and fluffy. Add vanilla and water and continue beating until well combined. Stop and scrape bowl.
Add flour and pecan pieces to butter mixture. Slowly begin mixing until everything is well combined but do not over mix.
Roll out dough between two sheets of waxed paper to about 1/4" thick. Cut desired shapes.
Place an inch apart on a parchment or silicone mat lined baking sheets. Bake for 15-18 minutes in a 325 degree (F) preheated oven. When done, remove from oven and allow to cool completely.
In a small bowl, add powdered sugar. Add 2-3 cookies at a time in sugar and gently toss to coat. Repeat until they're all done.