Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a mixing bowl, cream together the coconut sugar, coconut oil, and water until smooth and fluffy.
Add the brown rice flour, white rice flour, cornstarch, xanthan gum, cinnamon, baking soda, and salt, and mix until it forms a dough. It should have the texture of cookie dough. If the dough appears too crumbly add 1/2 teaspoon of water at a time until it reaches the good consistency.
Roll out the dough between two sheets of parchment paper to a 1/4-inch thickness. Using a sharp knife, cut the dough into about 18 rectangles. You can use a cookie cutter if you prefer or cut them into the shape you want. Transfer the cookies to the prepared baking sheet.
Bake for 10-12 minutes, or until golden brown. The cookies might be a bit soft but will harden once cooled.
Store the cookies in an airtight container at room temperature for up to 3 weeks.