Make the dough
1-In a large bowl, combine the sweet: In a large bowl, combine the sweet rice, almond, oat, and tapioca flours with the ¼ cup sugar, baking powder, and salt. Whisk to combine.
2-Add the butter slices (and citrus zest,: Add the butter slices (and citrus zest, if you’re using any). Blend with a pastry cutter or your fingertips until the butter is broken down into the size of small peas.
3-If you’re using fresh or dried fruit,: If you’re using fresh or dried fruit, toss them in at this time. Pop the flour mixture in the fridge for 10 minutes or longer to cool the butter back down.
4-Whisk together the 6 tablespoons cream, egg,: Whisk together the 6 tablespoons cream, egg, and vanilla (if using) in a measuring pitcher. Chill until needed.
5-Remove the flour mixture from the refrigerator: Remove the flour mixture from the refrigerator. (If you’re using frozen fruit, toss it in now.) Gradually add the cream mixture, working with a flexible silicone spatula until the dough holds together when you give it a squeeze. If the dough is too dry, add a few drops of cold cream directly to the floury bits.

Shape
6-Gently but firmly press the dough together: Gently but firmly press the dough together with your hands and shape it into a rough ball. Place on a piece of beeswax wrap or plastic wrap and form it into a disk that measures 6 inches across and about 1 ¼ inches high. Don’t worry about overworking the dough since there isn’t any gluten to toughen here!
7-Wrap and chill the dough disk until: Wrap and chill the dough disk until firm, at least 30 minutes and up to overnight.

Bake
8-When ready to bake, position a rack: When ready to bake, position a rack in the uppermost spot of your oven and preheat to 425ºF. Stack a rimmed baking sheet atop a second rimmed baking sheet and line with parchment paper. This will all keep the scones’ bottoms from over-browning.
9-Remove the dough round from the refrigerator,: Remove the dough round from the refrigerator, unwrap and place on a cutting board dusted lightly with oat flour. Brush the top of the scone with a little cream and sprinkle lightly with sugar. Use a large, sharp chef’s knife to cut the scone into 8 wedges and place the wedges on the prepared baking sheet, spaced well apart.
10-Bake the scones until golden on top: Bake the scones until golden on top and cooked through, 20-25 minutes, rotating the pan after 15 minutes to brown them evenly.
11-Remove from the oven and transfer the: Remove from the oven and transfer the scones to a wire rack. Let cool until warm, 10-20 minutes; they are still baking from residual heat. Serve warm or at room temperature.