Preheat oven to 425°F. Sift all of the dry ingredients (brown rice flour through baking soda) into a mixer bowl. Using the paddle attachment of an upright mixer (or a hand-held mixer), mix the dry ingredients with the butter until the mixture resembled coarse breadcrumbs.

In a medium mixing bowl, whisk together the mashed sweet potato, brown sugar and buttermilk. Pour this into the dry mixture, then mix briefly just until combined. (You may need a bit more buttermilk to make the dough come together - dough should be slightly tacky with no dry pieces.)

Dust a cutting board generously with rice flour, then pat the biscuit dough into a ¾-inch thick disk. Cut into 9 biscuits with a biscuit cutter. (Extra dough may be re-patted and cut to yield a total of 9 biscuits.)

Arrange biscuits snuggly on a lightly ­greased baking sheet, close enough so they’re almost touching. Bake on the middle oven rack for 20 to 25 minutes, until lightly golden on top and browned on the bottom. Rotate pan once during cooking. Serve warm or at room temperature. Biscuits are delicious drizzled with honey.  Makes 9 biscuits.

*Dairy-free option: Use 3 tablespoons soy milk + 1/2 teaspoon distilled vinegar to replace buttermilk.