Preheat the oven to 425°F. Line a baking sheet with parchment paper. Set cranberries on a cutting board. Chop into small, but still discernable pieces and set in a small bowl.
Place flour blend, xanthan gum, baking powder, 1/4 cup sugar and salt in a mixing bowl, or bowl of your stand mixer, and whisk until evenly combined. With your fingers, 2 forks or a pastry cutter, work the butter into the mixture until thoroughly distributed. Mix in the chopped cranberries.
Place the buttermilk, egg, vanilla and lemon zest in another bowl and beat to combine.
Pour wet ingredients over the gluten free flour mixture and mix well until a dough forms. (Its consistency will be somewhat like cookie dough.)
Transfer dough to prepared baking pan. Press and shape into a ball. Now flatten and shape into a 7-inch wide disk. Cut dough in half, and then cut each half into 5 wedges. Set the wedges about 3” a part on the baking sheet. Sprinkle the top of each wedge with a little sugar.
Bake scones 12 to 13 minutes, until rich golden. Cool at least 10 minutes before serving.
Note: The gluten free flour blend, baking powder and xanthan gum are all available in our baking supply aisle.