Preheat your oven to 325°F.
Zest and juice your orange. Set the juice aside for the glaze later. In a large mixing bowl, combine the sugar and orange zest. Rub them together with your fingers to release the fragrant oils. This helps infuse the sugar with the orange’s aroma.
Add the remaining dry ingredients to the bowl with the sugar and whisk well to combine.
Next, add the butter to the dry ingredients. Using a fork or pastry blender, work it in until the mixture resembles coarse crumbs with pea-sized pieces of butter remaining.
In a small bowl, whisk the egg and additional yolk together. Pour into the dry mixture and stir until a shaggy dough forms and starts to hold together.
Now, to shape the dough. Line a baking sheet with parchment paper and lightly dust it with tapioca starch. Transfer the dough onto the sheet, dust the top with more tapioca starch, and gently pat into a 7–8 inch round. It doesn’t need to be perfect, but aim for an even thickness so the scones rise well. Using a sharp knife, cut a “plus sign” into the dough to make 4 sections, then cut each section in half to create 8 triangles (you’ll end up with a “+” and an “X”). Do not separate the scones yet, grain-free dough is delicate. Bake for 20–22 minutes.
While the scones bake, prepare the frosting. Whisk together all frosting ingredients in a small bowl until smooth. Set aside.
Separate and finish baking the scones. Carefully remove the scones from the oven. Using a sharp knife, follow the cuts you made earlier to gently separate the triangles just slightly from one another. Return to the oven and bake for an additional 6–8 minutes until golden and set.
Let the scones cool completely, then generously frost with the gingerbread glaze. Serve and enjoy!