Step 1Heat the oven to 400 degrees.
Step 2Cream together the butter and sugar until light and fluffy, 3 to 5 minutes.
Step 3Add the vanilla and water and mix thoroughly. Gradually add the flour and salt, then the pecans. Shape the dough into 1 1/2-inch crescents and place on a greased cookie sheet. Bake until lightly browned, about 8 minutes.
Step 4Roll the cookies in powdered sugar while still warm, then cool on a rack.