I found this recipe in the SF Chronicle back in June 2011. I have been enjoying making these cookies and sharing them with family and friends. Enjoy!

Makes 3 dozen cookies

1 ½ cups brown rice flour
2 tablespoon tapioca flour
¾ cup quinoa flour
1 teaspoon xanthan gum (can find at Whole Foods)
1 teaspoon baking soda
8 ounces unsalted butter, softened
1 ¾ cup light brown sugar
1 teaspoon kosher salt
1 large egg, room temperature
1 large egg yolk
2 tablespoons sour cream
1 tablespoon vanilla extract
2 cups chocolate chips 
1 cup chopped lightly toasted nuts (optional)

Position the rack in the center of the oven and preheat the oven to 35 0degrees. Line a baking sheet with parchment.

Mix together brown rice flour, tapioca flour, quinoa flour, xanthan gum and baking soda in a bowl; set aside.

Cream butter, sugar and salt in the bowl of an electric mixer with paddle attachment, until light and fluffy, about 1 minute. Scrape down the bowl. Add the egg, egg yolk, sour cream and vanilla, and mix until fully incorporated. Scrape down the bowl. Add the flour mixture, and mix until well combined. Stir in the chocolate chips and nuts, if using. Chill dough for 30 minutes to make it easier to handle.

Form heaping tablespoons of dough into balls; space about 2 inches apart on the prepared baking sheet. Gently press the tops down to help the cookies spread evenly. Bake for approximately 8 minutes then rotate the baking sheets and bake another 3-5 minutes more. These cookies tend to be light in color when fully bakes. Let cool a few minutes on the baking sheet, then remove to a wire rack to cool completely.