1Heat oven to 350°F. Spray cookie sheet with cooking spray (without flour).
2In small bowl, mix flours, cocoa, xanthan gum, salt and baking soda. In medium bowl, beat egg, oil, 1 cup sugar, the vanilla and milk with electric mixer on medium speed until well blended. Gradually add flour mixture, beating until blended. Stir in chocolate chips and nuts.
3In small bowl, place 2 tablespoons sugar. Shape dough into 1 1/2-inch balls; dip tops in sugar. Place on cookie sheet.
4Bake 15 to 17 minutes or until set. Cool 5 minutes; remove from cookie sheet to cooling rack.