Preheat oven to 400° F. Prepare a baking sheet by lining with a silicone mat or parchment paper, or spray lightly with cooking spray.
In a medium bowl, sift gluten free flour, guar gum, sugar, baking powder, salt and lemon or orange zest.
Using a pastry blender, fork, or hands, add the cubed butter and blend until coarse and crumbly.
Add the milk and stir until combined. Add ¾ cups white chocolate chips and cranberries. Using your hands, combine the dough by pressing and kneading until everything is incorporated. The dough will be slightly sticky, but if you have troubles lightly wet your hands when working with the dough.
Divide the dough into two equal pieces and flatten each piece with your hands into a round disc, approximately 8 inches in diameter and 1 inch thick. Using a sharp knife, cut each round into 8 equal triangles. You should have 16 scones now. Place them on your baking sheet, at least 1 inch apart.
Bake for 9-11 minutes. Remove from oven and allow to cool before frosting.