Preheat the oven to 350*.Have ready two baking sheets.
Prepare the cookie base:.
in a medium bowl, stir the flour, baking soda, granulated sugar, brown sugar, water and vanilla until smooth, about 30 seconds.
Stop the mixer and scrape down the sides of the bowl, as needed during mixing.
add the flour mixture, mixing just until the flour is incorporated.
Stir in the chocolate chips.
leaving a 3" border on all sides, use a thin metal spatula to spread half of the dough on one baking sheet into a rough rectangle that measures about 11 x8" and is about 1/4" thick.
use the palms of your hands to help pat it into an even layer.
Repeat with the remaining cookie dough on the second baking sheet.
Bake one baking sheet at a time until the top looks dull -- not shiny -- and feels firm at the edges and center -- about 14 minutes.
as soon as each baking sheet comes out of the oven, sprinkle 1/4 cup of the chocolate chips over the cookie slab. Let the chocolate chips over the cookie slab.
let the chocolate chips sit for 5 minutes to soften and melt, then use a small metal spatula to spread the melted chocolate over the cookie.covering most of the cookie.
while the chocolate is still warm, sprinkle half the peppermint candy evenly over the slab.
let the cookie bark cool on the baking sheets on a wire rack until the chocolate topping is firm, about 2 hours.
or, to speed the cooling, cool the cookies on the baking sheet for about 30 minutes.then refrigerate them, still on the baking sheets, just until the chocolate topping firms, then remove from the refrigerator. the cookie bark will become crisp as it cools.
Break each cookie slab into about 12 5-6" long irregular pieces.
the cookies can be stored layered between sheets of wax paper in a tightly covered container at room temperature for up to 5 days.